Firefighters extinguish small grass fire outside Fremont Tesla plant

Fremont Fire Department says a small grassfire outside Tesla's Fremont plant has been extinguished Thursday evening.

The fire was reported at 5:20 p.m. at Tesla at 45500 Fremont Blvd., when a cardboard pile caught fire, and then caught a structure and some grass on fire, Fremont Fire Department Division Chief Diane Hendry said.

"The situation was complicated because power lines in the area had also caught fire along with a power pole," said Fremont Fire Division Chief Doug McKelvey.

Elon Musk, Tesla's CEO, tweeted that he was just at the factory and that the cardboard was being "prepped for recycling." He was appreciative of the the fire department's swift response. "No injuries or damage to the factory," he said.

"It's still burning in there," said McKelvey. "We are getting assistance from Telsa. They have an excavator. The excavator is helping pull these bales apart so we can get the water into and among the cardboard. Once a fire gets in a bale it's actually pretty hard. It needs to be broken apart."

Firefighters remain at the scene where the fire was said to be put out just before 6:30 p.m.

No injuries have been reported and only about a quarter acre of grass has burned.

"It's all under control," Hendry said.

Investigators have been called to Tesla but it will probably be Friday before fire officials can say what the cause and origin of the fire was, Hendry said.

People in the area posted their vantage point of the thick-black smoke on social media before the smoke turned white, an indication firefighters were gaining the upper hand.

Alameda County Fire Department told KTVU the fire was not at the Tesla factory, but north of the plant.

Skyfox captured some footage of the fire from overhead

This is a developing story.

Bay City News service and KTVU's Azenith Smith contributed to this story