An off-duty Los Angeles County firefighter has fatally shot a fellow firefighter and wounded another at their small community fire station before going to his nearby home, setting it on fire and apparently taking his own life.

A 44-year-old fire specialist died and a 54-year-old firefighter was shot when the gunman opened fire on Tuesday morning (local time) at Fire Station 81 at Santa Clarita, about 70 kilometres north of Los Angeles, Fire Chief Daryl Osby said.

The wounded man was in critical but stable condition at a hospital.

The shooter was a firefighter specialist and engineer, authorities said. The fire chief said he could not speak to the motive for the attack and did not know about any disciplinary actions.

Tweet from @KMedefer

The gunman, who was not identified, then went to his house less than 16km away, which authorities found engulfed in flames. He was later found dead in an empty pool.

The shooter appeared to have a self-inflicted gunshot wound to the head, Los Angeles County Sheriff Alex Villanueva said.

The shooting comes less than a week after a gunman killed nine of his co-workers at a rail yard in San Jose after rigging his home to burn down.

He killed himself last Wednesday after expressing hatred for his workplace for years.

Lifeline 131 114

beyondblue 1300 224 636

-AAP