EMERYVILLE, Calif. (AP) _ A tanker truck exploded into a huge mushroom cloud of smoke and flames, killing the driver, injuring at least seven people and damaging a section of freeway that carries 70,000 vehicles a day.

The tanker, loaded with 6,000 gallons of a butane-petroleum mixture, struck a divider about 9 a.m. Sunday, punching a hole in the tank and sliding along a metal railing. The friction ignited the fuel and blew the truck to shrapnel.

``It sounded like a bomb,'' said Tem Phitt of San Francisco, who suffered minor injuries. ``My car was burning on the outside and I got out. I didn't want to die in my car.''

At least seven people were treated for burns, including an Oakland family of four going to church in San Francisco. Five cars were damaged from flying debris.

The crash closed the highway, known as the MacArthur Maze, which is the main interchange between Oakland, Berkeley and San Francisco.

Crews worked through the night on the ramp from westbound I-80 to eastbound I-580, but Caltrans spokesman Greg Bayol said today's morning commuters ``shouldn't plan on it being open.''

The driver may have been traveling too fast around the interchange curve, said CHP spokeswoman B.J. Whitten. The identity of the driver, whose body was found in bushes below the highway, wasn't released Sunday.

The truck belonged to Button Transportation of Dixon and was part of a five-truck convoy contracted to transport the fuel from the Chevron refinery in Richmond to Bakersfield, according to Chevron spokeswoman Bonnie Chaikind.

Joe and Marsha Washington were with their teen-age sons Kenneth and Jerold, approaching the San Francisco-Oakland Bay Bridge when their car was engulfed by flames from the accident below.

They immediately fled their car, which was destroyed. All four were treated for minor burns.

``All of the sudden there was a great humongous ball of orange fire everywhere. It seemed like we drove through it forever. It was unbelievable, something you can't explain,'' Joe Washington told KCBS radio.