May 2020 CCPS Process Safety Beacon (Permitted Work - A Special Cause)
"On November 9, 2010, in upstate New York, USA, a contractor was welding new support brackets on a tank for water-based polymer slurry. The area outside the tank had been monitored for flammables and approved for hot work, but the inside of the tank was not tested. An explosion occurred; one person was killed and another one received first-degree burns and other minor injuries..."