OAKLAND, Calif. – A stretch of highway near the San Francisco-Oakland Bay Bridge collapsed Sunday after a gasoline tanker crashed and burst into flames, a loss that officials said could leave freeways leading to one of the nation’s busiest spans in near paralysis at rush hour. Officials said traffic will be disrupted for weeks, if not months.

Flames shot 200 feet in the air and the heat was intense enough to melt part of the freeway and cause the collapse, but the truck’s driver walked away from the scene with second-degree burns. No other injuries were reported in the 3:45 a.m. crash, which officials said could have been deadly had it occurred at a busier time.

“I’ve never seen anything like it,” Officer Trent Cross of the California Highway Patrol said of the crumpled interchange. “I’m looking at this thinking, ‘Wow, no one died,’ that’s amazing. It’s just very fortunate.”

Authorities said the damage could take months to repair, and that it would cause the worst disruption for Bay Area commuters since the 1989 Loma Prieta earthquake damaged a section of the Bay Bridge itself.

Nearly 75,000 vehicles use the portion of the road every day. But because the accident occurred where three highways converge, authorities said it could cause commuting problems for hundreds of thousands of people. State transportation officials said 280,000 commuters take the bridge into San Francisco each day.

On Sunday the collapse doubled the half-hour trip drivers normally face getting to and from San Francisco and the eastern suburbs, even though many didn’t even attempt the trip because of the crash. Traffic appeared light on the bridge itself, but motorists looking to get on and off were backed up on both sides.

Transportation officials said they already had added trains to the Bay Area Rapid Transit light rail system that takes commuters across San Francisco Bay, and were urging people to telecommute if possible.

State officials said motorists who try to take alternate routes Monday instead of relying on public transportation would face nightmarish commutes.

The tanker carrying 8,600 gallons of gasoline ignited after crashing into a pylon on the interchange, which connects westbound lanes of Interstate 80 to southbound I-880, on the edge of downtown Oakland about half a mile from the Bay Bridge’s toll plaza.