A fiery traffic crash on Interstate 70 in Jefferson County on Thursday afternoon left multiple people dead and shut down the highway in both directions. Eastbound lanes remained closed late into the night and may be closed for the morning rush hour Friday.

The crash involved 12 cars and three semis, according to Lakewood police. Six people from the crash and resulting fire were taken to a hospital. Lakewood police tweeted at 9 p.m. that there were multiple fatalities in the crash. A specific number was not provided.

A West Metro Fire Rescue firefighter was also injured by an explosion, fire officials said. The firefighter was hit by debris, likely an exploding tire. His injuries were described as minor.

Lakewood police, firefighters and other emergency personnel responded after receiving a call at 4:50 p.m., Lakewood police spokesman Ty Countryman said.

According to a preliminary investigation, a driver lost control of a semi-truck and plowed into standstill traffic underneath a bridge, resulting in explosions and fire as several vehicles were hit, Countryman said. At least one truck was carrying lumber, and a diesel spill and other fluids added fuel to the fire.

Countryman described the incident and scene as “devastation.”

Traffic on I-70 where the crash occurred had backed up because of an earlier crash, Countryman said.

That crash happened on I-70 near Ward Road and involved a school bus and semi-truck. Only minor injuries were reported, but eastbound lanes of the highway were briefly shut down.

A bridge over the Denver West crash site was damaged in the blaze, and engineers from the Colorado Department of Transportation responded to check its stability. There was also road damage from the fire.

At 7:15 p.m., officials said the highway would remain closed in both directions for several more hours at least.

About 9 p.m., CDOT announced that westbound lanes are open at Denver West Boulevard with a detour in place. Eastbound lanes, starting at West Sixth Avenue, remained closed and could stay that way into the Friday commute.

Drivers who used the eastbound stretch of highway are urged to make plans for an alternate route.

The driver of the runaway truck was among the six people who were injured and taken to a hospital, Countryman said. The fire on the highway had burned so intensely that hot spots were still a concern at 9 p.m.