PHOENIX (AP) - Pressure in a "gas ax" used by police to break down walls and subdue suspects may have caused one of the devices to malfunction and kill an officer during a training exercise, authorities said.
Scottsdale police Sgt. Tom Hontz was killed and 11 other officers slightly injured Wednesday when the device exploded during the exercise at two vacant homes in suburban Gilbert, police said.
Authorities issued a nationwide warning to law enforcement agencies about the device and asked the U.S. Bureau of Alcohol, Tobacco and Firearms to determine the cause.
"The reason the thing exploded is there was too much pressure inside of it," said Sgt. Jim Lahti, a Gilbert police spokesman. "We are investigating why."
The gas ax is used to make a hole in a wall of a room where a suspect is barricaded and emits a debilitating gas that gives police a chance to enter safely. A long metal handle is used to drive a pointed pipe through a wall. A tear gas or similar chemical cartridge is then triggered.
Hontz, 45, died a few hours after the explosion. Other officers involved in the training were treated and released, including one with shrapnel injuries from flying metal.