(CNN) -- Traffic on Interstate 15 in Southern California was backed up for miles early Tuesday after a new overpass in the city of Hesperia caught fire, a fire official said. The major artery between Los Angeles and Las Vegas is expected to be closed for up to 48 hours while crews put out the fire and demolish the damaged structure, according to Eric Sherwin with the San Bernadino County Fire Department. The bridge caught fire Monday when sparks from blowtorches used to cut reinforcing bar ignited the wooden framework supporting the structure. Hesperia is about 60 miles northeast of Los Angeles. College tour in California ends in fiery wreck, leaves 10 dead .
Interstate 15 is shut down between Los Angeles and Las Vegas . A new overpass caught fire in Hesperia, California . Blowtorches ignited the wooden structure under the bridge .