Two police officers were injured Wednesday in what police described as an "industrial accident" during a K-9 training exercise in South Gate.
Fire crews responded to reports of an explosion at 5612 Imperial Highway in South Gate around 5:45 p.m.
Both officers "were conducting a canine training exercise inside an unoccupied commercial building," sheriff's officials said in a statement early Thursday. "During the training, there was an electrical fire that resulted in both officers being seriously burned."
They were the only people still in the building when the fire sparked without warning, said Lt. Joe Mendoza of the Los Angeles County Sheriff's Department's Homicide Bureau.
The officers and their K-9 partners were taken to a hospital. Authorities said the officers suffered burns to their face and their upper bodies. The dogs did not suffer significant injuries, police added.
They were in "fair condition and improving" as of Thursday morning, sheriff's officials said. Both were expected to survive.
One of the veteran officers was from the South Gate Police Department and another was from the Downey Police Department, South Gate police Capt. Darren Arakawa said.
What caused the electrical fire was unknown, but the investigation was ongoing.
"We are collecting anything that may have evidentiary value out of an abundance of caution," Mendoza said. "Better to have and not need than need and not have."
Mendoza said the officers had not been interviewed as of Thursday morning.
Toni Guinyard and City News Service contributed to this report.