Three people died and at least 10 were injured in a fiery 15-truck pileup in a Los Angeles-area freeway tunnel, according to sources from the California Highway Patrol.

The domino-effect pileup started when two trucks collided on wet, slippery roads around 11 p.m. Friday night. Flames were still shooting from the tunnel Saturday morning creating an impasse on I-5, roughly 30 miles northwest of downtown L.A.

Wreckage from the crash filled the southbound truck tunnel, which stretches for more than a half mile. Flames shot up over 100 feet during the height of the blaze. "It looked like a bomb went off," said Scott Clark, an L.A. country firefighter who was among 300 battling the fire throughout the night.

Twenty people were able to get out of the tunnel after the crash. Another 10 were taken to the hospital with injuries. It was unclear whether a truck driver whose remains were found Saturday afternoon was a man identified as missing following the accident.

Although the tunnel is intended specifically for trucks, it is open to car traffic, and authorities are concerned there may be smaller vehicles in the wreckage.

The accident blocked major traffic arteries near Santa Clarita that feed into the highway through which the tunnel runs, leaving many drivers unable to move on the roads for more than seven hours.

By mid-morning Saturday, most of the flames had been extinguished with a high-expansion foam that firefighters injected into the tunnel to smother the blaze, and firefighters began hauling debris out of the tunnel.

Officials hope to reopen the southbound lanes of Interstate 5 by Tuesday morning, but they have been hampered by small lingering fires and concern about whether the tunnel is safe to drive through.

It's "extremely difficult for the crews," said Inspector Jason Hurd of the Los Angeles County Fire Department. "There's only been, obviously, two means of [entry] and exit attacking this fire, and the intense heat; again, not knowing the number of vehicles, the type of vehicles inside, their cargo have all been cause for concern for us."

The freeway, part of the major route that runs north-south from San Francisco to Los Angeles, is expected to be closed for at least another day while the wreckage is cleared. Traffic across the state may be snarled much longer if the fire caused major structural damage.