Applebee's fire in Antioch investigated as possible arson

The fire that broke out Thursday morning in Applebee's restaurant in Antioch is being investigated as a potential case of arson, the Antioch fire department confirmed with KTVU.

The fire alarm went off around 4:15 a.m. at the Applebee's on Hillcrest Avenue.

Smoke was seen coming out of the window and several of the eating booths were covered in flames, the fire crew said.

SEE ALSO: Fire displaces dozens of residents from Antioch apartments

The Contra Costa Fire Protection District said someone broke a window and set part of the dining area on fire.

The restaurant sprinklers kept the fire from spreading.

Fire Marshal Chris Bachman said those sprinklers almost certainly averted further damage.

"It did its job. The alarm went off that there was water flow," Bachman said.

Authorities are looking into whether a passerby or perhaps a disgruntled customer or worker started the fire. 

In a statement sent to KTVU on Friday, Frank La Maina, Applebee's director of operations, noted that the fire happened outside of business hours and he was thankful no one was there or hurt. He added that the restaurant is working with authorities to investigate what happened.