A category 5 (the most destructive) tornado hit Moore, Oklahoma on May 20th, destroying the town and killing 24. Of those killed, 7 were elementary school children, who drowned when water mains burst in the basement where they were sheltered.
Examining this tragedy can help provide lessons to reduce the risk of this issue happening again. We can analyze the tornado impact at the most severely impacted elementary school in a Cause Map, in order to visually diagram the cause-and-effect relationships that led to the tragic deaths.
First, we determine the impacted goals. In this case, all other goals are overshadowed by the deaths of seven elementary students, and injuries to dozens. In addition, the school was completely devastated (demonstrating the unbelievable destructive power of the tornado), resulting in early school closure and intense rescue, recovery and cleanup.
To perform our root cause analysis, we begin with the safety goal and ask “Why” questions. The deaths in this case are reportedly due to drowning, which occurred when children in the basement (a recommended sheltering location in the case of tornadoes) drowned due to water from bursting water mains. The specific failure mechanism of the failure is not known (and may never be due to the extreme levels of damage) but is likely related to the direct strike of the tornado, which is common in the area (close to the center of tornado alley).
Students who were injured by crushing and asphyxia were in the hallways and bathrooms of the school. (These are recommended sheltering locations for buildings that don’t have basements.) It is remarkable that, despite the complete annihilation of the school, students who were sheltered in hallways and bathrooms all survived, thanks in many cases to teachers protecting them with their own bodies. A 16-minute warning from the National Weather Service combined with carefully rehearsed crisis plans that were put into action, allowed the best possible protection for students in a school without a safe room or storm shelter.
This storm has reignited the discussion about expectations for safety shelters in public places that are prone to natural disasters. The devastating loss at the school has also raised the safety issue of ensuring that the locations used for shelter are cleared of other potential hazards, such as water mains and fire risks. Because of the relatively short warning time (16 minutes in this case, which is above average) before a tornado strikes, emphasis on tornado drills and safety plans should continue.
To view the Outline and Cause Map, please click “Download PDF” above. Or click here to read more.