Two members of the Los Angeles Fire Department are “making progress” after sustaining critical injuries while fighting a semi truck fire that led to an explosion on Thursday, according to a department spokesperson.

Nine firefighters were injured in Wilmington by the catastrophic explosion of a tank of compressed natural gas used to power the truck, including two who were hospitalized, fire officials said.

One of those firefighters was discharged Friday night, and another is “critical but stable” and remains in the intensive care unit at Los Angeles General Medical Center, which operates a burn unit, Los Angeles Fire Department Public Information Officer Erik Scott said in a statement Saturday.

The latter firefighter has been taken off a ventilator, Scott said.

“With a happy heart and a sense of relief, we are pleased to report that our most injured #LAFD #Firefighter was successfully extubated this morning. He is awake, alert and talking. Next steps will be to introduce food as tolerated,” Scott posted to X.

The other seven firefighters “have various medical appointments and remain off duty due to their injuries,” Scott said. Some of the firefighters sustained burns, blunt-force trauma, injuries from shrapnel and hearing problems from the explosion, he said.

The cause of the explosion, which shot 30-foot flames into the air early Thursday morning at 1120 Alameda St., is still under investigation.

Firefighters responded after receiving a call that the truck had caught fire. The driver was unharmed and told officials she stopped driving after noticing “abnormalities” with the vehicle.