Stinson beach explosion, fire damages buildings and closes section of Highway 1

 Marin County investigators spent a good portion of Tuesday cleaning up and trying to figure out what touched off an explosion and fire in Stinson Beach. 

Highway 1 was closed for most of the day as investigators put out the fires caused by that explosion, and launched an investigation into what happened to set it off in the first place.

From above the aftermath was stunning. California Highway Patrol provided aerial video of thick black smoke that showed a roaring fire and debris from the explosion scattered out onto Shoreline Highway. 

A building housing a realty company and apartments were destroyed in the blaze that was reported shortly after 8:40 a.m. 

Neighbor Gary Marseilles said he didn't see the explosion, but he felt and heard it. 

"Kaboom," said Marseilles. "I thought it was an avalanche it was so forceful. When I came from my house, my neighbors were coming out of their house."

Marseilles said his first instinct was to make sure everyone was ok. 

"I had no thought of calling 911. I ran straight to the building, to go inside and see if my friend Al Engle, the owner, was in there. He's 95-96 years old." 

Turns out Engle wasn't inside. However, firefighters did say two other people were inside the building and they did receive minor injuries
 but declined treatment. 

"The bookkeeper Helen was in the building when it blew," said Marseilles. "But, she got out immediately, no injuries."

 In all, four buildings were damaged by the explosion and ensuing fire including the Sand Dollar Restaurant. 

Crews from Stinson Beach, Southern Marin, and Marin County Fire Department responded to smother the fire, spending much of the day clearing debris, and trying to figure out what caused the explosion. 

At last check, fire officials said they were still trying to determine if the fire was an accident or foul play.