Asphyxia (KV 78)


What Happened?

On November 15, 2011, a utility laborer and a maintenance mechanic were inside a 9’ deep 300 gallon water tank. They were scraping and removing old paint from inside the tank. The paint stripper they were using contained methylene chloride that is used to dissolve old paint, which could not be scraped off. An unknown amount of time had passed when the two workers were found inside the tank unconscious. They were both pulled from the tank by co-workers. The utility laborer was pronounced dead and the maintenance mechanic was left in critical condition. Cause of death was determined to be chemical asphyxiation.

Contributing Factors

A 2-Minute Drill would have prevented the workers from entering the tank with any chemicals. Furthermore, the Proper PPE was not worn and the confined space permit was non-existent.

What Can We Learn?


If the proper Procedures were followed they would have ensured there was proper ventilation and were using the proper chemicals for a confined space.  

By using a Critical Step Check, the workers would have identified that they were to avoid entering the tank with any chemicals.


Overconfidence caused the laborers to overestimate their knowledge, underestimate the risks, and exaggerate their ability to control events. 

Lack of properly assessing the Physical Environment led the laborers to continue work in hazardous conditions.

Ask the Right Questions

How does this relate to our work?

Where do we have similar traps?

What Tools can we use to avoid a similar incident?

Was a stop work point missed?