Tag Archives: public safety

Root Cause Analysis - Incident Investigation

Landslide of construction debris buries town, kills dozens

By ThinkReliability Staff

Shenzhen, China has been growing fast. After a dump site closed in 2013, construction debris from the rapid expansion was being dumped everywhere. In an effort to contain the waste, a former rock quarry was converted to a dump site. Waste at the site reached 100 meters high, despite environmental assessments warning about the potential for erosion. On December 20, 2015, the worries of residents, construction workers and truckers came true when the debris slipped from the quarry, covering 380,000 square meters (or about 60 football fields) with thick soil as much as 4 stories high.

A Cause Map can be built to analyze this issue. One of the steps in the Cause Mapping process is to determine how the issue impacted the overall goals. In this case, the landslide severely impacted multiple goals. Primarily, the safety goal was impacted due to a significant number of deaths. 58 have been confirmed dead, and at least 25 are missing. The environmental goal and customer service goal were impacted due to the significant area covered by construction waste. The regulatory goal is impacted because 11 have been detained as part of an ongoing criminal investigation. The property goal is impacted by the 33 buildings that were destroyed. The labor goal is also impacted, as are more than 10,600 people participating in the rescue effort.

The Cause Map is built by visually laying out the cause-and-effect relationships that contributed to the landslide. Beginning with the impacted goals and asking “Why” questions develops the cause-and-effect relationships. The deaths and missing persons resulted from being buried in construction waste. Additionally, the confusion over the number of missing results from the many unregistered migrants in the rapidly growing area. The area was buried in construction waste when waste spread over a significant area, due to the landslide.

The landslide resulted from soil and debris that was piled 100 meters high, and unstable ground in a quarry. The quarry was repurposed as a waste dump in order to corral waste, which had previously been dumped anywhere after the closure of another dump. Waste and debris was piled so high because of the significant construction debris in the area. There was heavy construction in the area because of the rapid growth, resulting in a lot of debris. Incentives (dumpsite operators make money on each load dumped) encourage a high amount of waste dumping. Illegal dumping also adds to the total.

While an environmental impact report warned of potential erosion, and the workers and truck drivers at the dump registered concerns about the volume of waste, these warnings weren’t heeded. Experts point to multiple recent industrial accidents in China (such as the warehouse fire/ explosion in Tianjin in August, the subject of a previous blog) as evidence of the generally lax enforcement of regulations. Heavy rains contributed to ground instability, as did the height of the debris, and the use of the site as a quarry prior to being a waste dump.

Actions taken in other cities in similar circumstances include charging more for dumping debris in an effort to encourage the reuse of materials and monitoring dump trucks with GPS to minimize illegal dumping. These actions weren’t implemented in Shenzhen prior to the landslide, but this accident may prompt their implementation in the future. Before any of that can happen, Shenzhen has a long way to go cleaning up the construction debris covering the city.

Root Cause Analysis - Incident Investigation

Lawsuit Questions the Safety of Guardrails

By Kim Smiley

A whistleblower lawsuit claims that tens of thousands of guardrails installed across the US may be unsafe.  The concern is that the specific design of the guardrail in question, the ET-Plus, can jam when hit and puncture cars, potentially causing injury, rather than curling away as intended.

This issue has more questions than answers at this point, but an initial Cause Map can be built to document what is currently known.  A question mark should be added to any cause that is suspected, but has not been proven with evidence.  As more information, both new causes and evidence, becomes available the Cause Map can easily be expanded to incorporate it.

In this example, the primary concern, both from a safety and regulation standpoint, about the guardrails are centered on a design change made in 2005.  The size of the energy-absorbing end terminal was changed from five inches to four.  The modification was apparently made as a cost-saving measure.   The lawsuit alleges that federal authorities were never alerted to the design change so it never received the required review and approval.  It appears that federal authorities were not alerted until a patent case bought up the issue in 2012.

The reduction in the size of the end terminals may have affected how the guardrails function during auto accidents.  The lawsuit claims that five deaths and other injuries from at least 14 auto accidents can be attributed to the new design of guardrails.  The Federal Highway Administration has stated that the guardrails meet crash-test criteria, but three states (Missouri, Nevada and Massachusetts) are taking the concerns seriously enough to ban further installation of the guardrails pending completion of the investigation.

This issue is a classic proverbial can of worms.  Up to a billion dollars could be at stake in the lawsuit and the man who filed the lawsuit could get a significant cut of the payout.  There are potential testing requirement issues that need to be considered if the guardrails are passing crash tests, but causing injuries.  There are concerns over whether the company properly informed the federal government about design changes, which is a particularly sensitive topic following the recent GM ignition switch issues.  All and all, this should be a very interesting topic to follow as it plays out.

To view a high level Cause Map of this issue, click on “Download PDF” above.

Root Cause Analysis - Incident Investigation

300,000 Unable to Use Water after Chemical Spill in West Virginia

By Kim Smiley

Hundreds of thousands of West Virginians were unable to use their water for days after it was contaminated by a chemical spill on January 9, 2014. About 7,500 gallons of 4-methyl-cyclohexane-methanol, known as MCHM, leaked out of a storage tank and into the Elk River.   At the time of the spill, little information was known about MCHM, but officials ordered residents not to use the use the water because the chemical can cause vomiting, nausea, and skin, eye and throat irritation.  The ban on water usage obviously meant that residents should not drink the water, but they were also told not to cook, bathe, wash clothes or brush their teeth with it.

The investigation into this incident is still ongoing, but some information is available.  An initial Cause Map, or visual root cause analysis, can be built now and it can easily be expanded in the future.  A Cause Map is used to illustrate the cause-and-effect relationships between the many causes that contribute to any incident.  In this example, it is known that the MCHM leaked into the river because it was being stored in a tank near the river and the tank failed.  MCHM was being stored in a tank because it is used in coal processing and it was profitable for the company to sell it.

The cause of the tank failure hasn’t been officially determined, but the company who owned the facility has stated that an object punctured the tank after the ground under the tank froze.  (Suspected causes can be included on the Cause Map with a question mark to indicate that more evidence is needed to confirm their validity.)

The tank in question was older, built about 70 years ago.  There were no regulations that required the tank to be inspected while it was being used to store MCHM because the chemical is not currently legally considered a hazardous material.  The tank is also an atmospheric tank so it is exempt from current federal safety inspections because it is not under pressure, cooled or heated.

Many are asking questions about why a tank full of a chemical that can make people sick that was so close to the water supply had so little regulation and no required inspections.  The debate that has been sparked by this accident will force a close review of current regulations governing these types of facilities.

It’s also alarming how little was known about this chemical prior to this accident.  It’s still not well understood exactly how dangerous MCHM is.  Experts have stated that the long term impacts should be minimal, but it would be awfully reassuring to the people living in the area if there was more information about the chemical available.

Companies need to have a clear understanding of the risks involved in their operations if they hope to reduce the risk to the lowest reasonable level and develop effective emergency response plans to deal with any issues that do arise.  As the old saying goes – failure to plan is planning to fail.  Just ask the company involved.  Freedom Industries filed bankruptcy papers on January 17, 2013 as a direct result of this accident.