An unexplained explosion Tuesday morning blew the front off of a building on the main drag in Stinson Beach, shook the town like an earthquake, and caused a fire that spread to neighboring businesses.

The explosion happened around 8:42 a.m. this morning on the 3400 block of Shoreline Highway, according to the Marin County Fire Department. Two buildings were destroyed in the blast, and two other buildings sustained damage, one of them major damage, as the Marin Independent Journal reports.

Photos and video from the scene on Twitter show significant wreckage. As the Chronicle reports, it's still unclear if anyone was injured or killed. The fire was reportedly under control as of 10:50 a.m.

Michelle Fox, who is staying two blocks away from the explosion, tells the Marin IJ, "It was brutal. I thought it was an earthquake and the roof over my house was caving in." And taking in the scene afterward, she said, "It looks like a warzone."

Highway 1 was closed while the area was cleaned up, and PG&E temporarily cut power to the area while the incident is being investigated.

Fire officials are telling people to avoid the area, and saying that the cleanup will last for most of the day.

This story will be updated as we learn more.