Plant Pathogen Threatens California Oak Trees

By Staci DeKunder

We are often overwhelmed by headlines addressing the latest disease outbreak facing the human population. In recent years, we have read with great concern about Ebola, measles, Avian flu, etc. Unfortunately, there is a similar outbreak facing oak trees in California. Sudden Oak Death is responsible for the death of over one million California oak and tanoak trees. And as it turns out, a microscopic pathogen called Phytophthora ramorum (P. ramorum) is behind the disease.

Matteo Garbelotto was one of the first two scientists to discover P. ramorum in 1995. Over 20 years later, scientists understand much more about how this tree killer operates and how it came in contact with the oaks.   P. ramorum thrive in humid environments, and can spread from plant to plant via wind, rain or with help from humans. Some plants are susceptible to the pathogen (like the California oak and the tanoak), and others are merely host carriers (California bay laurel, rhododendron and camellia). When a susceptible plant is infected, the pathogen attacks the tree’s bark, finding pathways into the tree. From there, it blocks the plants ability to circulate water and nutrients. This results in a fast demise for the tree, with symptoms of brown leaves and sap leaking from the bark.   If the pathogen finds a ‘host ‘plant, the plant is not harmed, but the pathogen can easily be transmitted to a nearby susceptible plant.   This is an issue both in nurseries and in the forest.   A simple Process Map can be created to depict how the pathogen wreaks its havoc on the trees.

As with most situations, understanding the problem is an important step to identifying solutions. Prior to discovering the pathogen P. ramorum, scientists were baffled by the bleeding trees. They initially suspected insects, but could find no visible wounds or damage typical of insects. Creating a Cause Map can help analysis the cause-and-effect relationships that are responsible for an impact to the goals. Asking ‘why’ questions beginning with the affected goal helps us to learn about the causes of an event. In this case, the environmental goal was impacted by the death of millions of trees. The hard work of Garbelotto and his fellow scientists showed that the trees were dying because they were exposed to the pathogen P. ramorum AND the fact that the trees were susceptible to its affects. The plants were exposed to the pathogen because the pathogen was carried from nearby plants. This was due to the fact that there were infected plants were located close by AND the presence of a mode of transportation. This mode of transportation could have been wind, rain and / or human transport. The human transport could be a result of people accidentally moving infected plants or soil.   There are infected plants close by because certain plants act as a ‘breeding ground’ for the pathogen AND because the pathogen was accidentally imported to the United States via host plants via the ornamental plant trade in the 1980’s. (Click on “Download PDF” above to see a Process Map and Cause Map of this issue.)

Fortunately, there are several identified solutions that can help minimize the impact of this pathogen. Using the Cause Mapping process, these solutions can be tagged to the specific causes that they impact. Then, a table of solutions can be created so that the owners (and due dates if applicable) can be tracked.   Five solutions are shown on Cause Map to help save the oak trees including: federally regulating the movement of host plants, using caution when moving plants and soil in infected areas, removing some host plants in infected areas, a phosphite spray which can be applied to infected trees and a smartphone application that can help educate and expand the current understanding of infected areas.

Marauding Monkeys Lead to Electrical Outage in Kenya

By Angela Griffith

One monkey managed to cause an electrical outage for all of Kenya – 4.7 million households and businesses – for 15 minutes to more than 3 hours. In order to determine solutions to prevent this from happening again, a thorough analysis of the problem is necessary. We will look at this issue within a Cause Map, a visual form of root cause analysis.

The first step of any problem-solving method is to define the problem. In the Cause Mapping method, the problem is defined with respect to the organization’s goals. In this case, there were several goals that were impacted. If the organization has a goal of ensuring safety of animals, that goal is impacted due to the risk of a fatality or severe injury to the monkey. (In this case, the monkey was unharmed and was turned over to the wildlife service.) The loss of power to 4.7 million businesses and households is an impact to the customer service goal. The nationwide power outage, which lasted from 15 minutes to over 3 hours, is an impact to the production/ schedule goal. Damage to the transformer is an impact to the property goal, and the time required for response and repair is an impact to the labor/ time goal.

The second step of problem-solving is the analysis. Using the Cause Mapping method, cause-and-effect relationships are developed. One of the impacted goals is used as the first effect. Asking “Why” questions is one way to determine cause-and-effect relationships. However, there may be more than one cause required to produce an effect. In this example, the power outage resulted from a cascading effect on the country’s generators. This cascading effect was caused by the loss of a hydroelectric facility, which provides 20% of the country’s electricity, and the unreliability of the power grid, due to aging infrastructure. All of these causes were required for this scenario: had the country had a more reliable power grid or more facilities so that the country was not so dependent on one, the loss of the hydroelectric site would not have resulted in nationwide outage.

Continuing the analysis, the loss of the hydroelectric facility was caused by an overload when a key transformer at the site was tripped. According to the power company, the trip was caused by a monkey falling onto the transformer. (There is also photographic evidence showing a monkey in the area of the transformer.) In order for the monkey to fall onto the transformer, it had to be able to access the transformer. The monkey in this case is believed to have fallen off the roof. How this occurred is still unclear, because the facility is secured by an electric fence designed specifically for protection against “marauding wild animals”.

The last step of problem-solving is to determine solutions, based on the analysis of this problem. The utility says it is “looking at ways of further enhancing security” at all their power plants. Unfortunately, total protection against outages caused by animals is impossible. In the United States, animal-caused outages are believed to cause at least $18 billion in lost economy every year. Just this May, raccoons caused outages to 40,000 in Seattle and 5,600 in Colorado Springs. This year also saw outages caused by squirrels, snakes, starlings and geese. Other unusual outages include work on a transformer causing an outage with economic loss of $118 million in Arizona (see our blog on this subject) and a woman with a shovel who cut internet service to nearly all of Armenia (see our blog on this subject).

Because power outages due to animals and other issues can’t be completely eliminated, ensuring a robust power grid is important to minimize the impact from and duration of outages. Calls for improvements to the aging infrastructure in Kenya have resulted from this incident, but these kinds of solutions require not only the cooperation of the utilities, but the country as a whole.

To view the problem outline and Cause Map for this incident, please click on “Download PDF” above

How Did a Cold War Nuclear Bomb Go Missing?

By Staci Dekunder

Is there a nuclear bomb lost just a few miles off the coast of Savannah, Georgia? It seems that we will never know, but theories abound. While it is easy to get caught up in the narrative of these theories, it is interesting to look at the facts of what actually happened to piece together the causes leading up to the event. This analysis may not tell us if the bomb is still under the murky Wassaw Sound waters, but it can tell us something about how the event happened.

Around 2 am on February 5, 1958, a training exercise was conducted off the coast of Georgia. This was during the most frigid period of the Cold war, and training was underway to practice attacking specific targets in Russia. During this particular training mission, Major Howard Richardson was flying a B-47 bomber carrying a Mark 15, Mod 0 Hydrogen bomb containing 400 pounds of conventional explosives and some quantity of uranium.

The realistic training mission also included F-86 ‘enemy’ fighter jets. Unfortunately, one of those jets, piloted by Lt. Clarence Stewart, did not see the bomber on his radar and accidentally maneuvered directly into the B-47. The damage to both planes was extensive. The collision destroyed the fighter jet, and severely damaged the fuel tanks, engine, and control mechanisms of the bomber.   Fortunately, Stewart was able to safely eject from the fighter jet. Richardson had a very difficult quest ahead of him: to get himself and his co-pilot safely on the ground without detonating his payload in a heavily damaged aircraft. He flew to the closest airfield; however, the runway was under construction, making the landing even more precarious for the two crew members and for the local community that would have been affected had the bomb exploded upon landing. Faced with an impossible situation, Richardson returned to sea, dropped the bomb over the water, observed that no detonation took place, and returned to carefully land the damaged bomber.

The Navy searched for the bomb for over two months, but bad weather and poor visibility did not make the search easy. On April 16, 1958, the search was ended without finding the bomb. The hypothesis was that the bomb was buried beneath 10 – 15 feet of silt and mud. Since then, other searches by interested locals and the government have still not identified the location of the bomb.   In 2001, the Air Force released an assessment which suggests two interesting points. First, the bomb was never loaded with a ‘detonation capsule’, making the bomb incapable of a nuclear explosion. (Until this time, conventional wisdom suggested that the detonation capsule was included with the bomb.) Second, the report concluded that it would be more dangerous to try to move the bomb than to leave the bomb in its resting place.

While we may never learn the location of the bomb, we can learn from the incident itself. Using a Cause Map, we can document the causes and effects resulting in this incident, providing a visual root cause analysis. Beginning with several ‘why’ questions, we can create a cause-effect chain. In the simplest Cause Map, the safety goal was impacted as a result of the danger to the pilots and to the nearby communities as the result of a potential nuclear bomb explosion. This risk was caused by the bomb being jettisoned from the plane, which was a result of the collision between the fighter jet and the bomber. The planes collided due to the fact that they were performing a training mission to simulate a combat scenario.

More details are uncovered as this event is further broken down to include more information and to document the impact to other goals. The property goal is impacted through the loss of aircraft and the bomb. The bomb is missing because it was jettisoned from the bomber AND because it was never found during the search. The bomb was jettisoned because the pilot was worried that the bomb might break loose during landing. This was due to the fact that the planes collided. The planes collided due to the fact that the F-86 descended onto the top of the B-47 AND because they were in the midst of a training exercise. The fighter jet crashed into the bomber because the bomber was not on radar. The planes were performing an exercise because they were simulating bombing a Russian target, because it was the middle of the Cold War. The search was unsuccessful because the bomb is probably buried deep in the mud AND because the weather and visibility were bad during the search.

Finally, the ‘customer service’ goal is impacted by the fact that the residents in nearby communities are nervous about the potential danger of explosion/radiation exposure. This nervousness is caused by the fact that the bomb is still missing AND the fact that the bomb contained radioactive material, which was due to routine protocol at the time.

Evidence boxes are a helpful way to add information to the Cause Map that was discovered during the investigation. For example, an evidence box stating the evidence from the 2001 Air Force report that the bomb had no detonation capsule has been added to the Cause Map. A Cause Map is a useful tool to help separate the facts from the theories. Click on “Download PDF” above to see the full, detailed Cause Map.

Kansas City Interstate Overpass Closed Due to 20′ Crack

By Angela Griffith

A bridge engineer watching a crack (previously described as “tight”) under the Grand Boulevard bridge noticed it had extended to 20′ on May 6, 2016. He immediately ordered the bridge closed, requiring the rerouting of the more than 9,000 vehicles that use the bridge every day. Replacing the bridge is estimated to cost $5 million.

Luckily, due to the quick action of the engineer, there were no injuries or fatalities as could have occurred due to either the bridge catastrophically collapsing while in use, or for motorists on the Interstate below being struck by large chunks of concrete falling from the overpass.

The overpass failure can be addressed in a Cause Map, or visual root cause analysis. The process begins by capturing the what, when and where of the incident (a bridge failure May 6 in Kansas City) and the impacts to the goals. Because there was the potential for injuries, the safety goal is impacted. The re-routing of over 9,000 vehicles a day is an impact to the customer service goal. The closing of the bridge’s overpass/ sidewalks is an impact to the production goal, and the cost of replacing the bridge is an impact to the property/ labor goal.

By beginning with an impacted goal and asking ‘Why’ questions, cause-and-effect relationships that lay out the causes of an incident can be developed. In this case, the impacted goals are caused by the significant damage to the bridge, due to a rapidly spreading crack.

The failure of any material or object, including all or part of a bridge, results from the stress on that object from all sources overcoming the strength of the object. In this case the stress on the bridge was greater than the strength of the bridge. Stress on the bridge results from each pass of a vehicle over the life of the bridge. In this case, 9,300 vehicles a day transit the bridge, which has been in service since 1963.

Stress also results from large trucks traveling over the bridge. The engineers suspect this is what happened, possibly due to an apartment construction project near the bridge. Says Brian Kidwell, an assistant engineer for the Missouri Department of Transportation, “My hunch is a very heavy load went over it. It could have been a totally legal load.” A “hunch” by an experienced professional is included in the Cause Map as a potential cause. This is indicated with a “?” and requires more evidence.

Legal loads on bridges are based on the allowable stress for a bridge’s strength. However, the strength of the bridge can change over the years. It is likely that happened in this case. Previous damage has been noted on the bridge, which also required bracing last month to fix a sagging section. However, the bridge was deemed “adequate” in an inspection eight months ago. Any needed repairs may not have occurred – there’s never enough money for needed infrastructure improvements. It’s also possible that water entered the empty cylinders that make up the part of the span of the bridge (this is called a “sonovoid” design) and they could have filled with water and later frozen, causing damage that can’t be easily seen externally.

For now, more information will be required to determine what led to the bridge failure. At that point, bridges of similar design may face additional inspections, or be replaced on the long waiting list for repairs. For Kansas City, some are taking a broader – and bolder – view and are recommending the older section of the Interstate “loop” be removed altogether.

To view the Cause Map of the bridge failure, click on “Download PDF” above. Or, click here to learn.