Roberto Y. Longoria, a 42-year-old tanker technician of Phoenix, died Aug. 29, 2021, while attempting to save his 32-year-old co-worker from suffocation inside a chemical tanker trailer in Avondale, Arizona. Jose Perez entered the trailer to try to fix a slow drain and became unresponsive. Longoria started to enter the trailer from its ceiling hatch, but then called 911 to report the incident, handed his phone to the truck driver to continue the call, retrieved a respirator mask from nearby, and then entered the trailer. Soon, he too, collapsed. Firefighters removed the men from the trailer; they died from exposure to hydrogen sulfide gas.