I-15 bridge collapse: When will the highway reopen?

A massive bridge being constructed over Interstate 15 in the Mojave Desert was a smoldering shambles of twisted metal and wood Tuesday after a metal-cutting accident set it ablaze, blocking a major route between Southern California and Nevada.

The blaze erupted Monday afternoon and snarled traffic as it burned through the night. Firefighters struggled to battle flames in the bridge's temporary wooden support structure as they contended with the danger of collapse, limited water supply and winds.

By morning, girders sagged onto the interstate below and crews were using heavy equipment to drag collapsed remnants out of lanes.

Despite the monumental mess, the California Department of Transportation district director, Basem Muallem, said he expected to have the northbound lanes open by Tuesday afternoon and the southbound side reopened by Wednesday morning.

[Update 5-7-14: All lanes of Interstate 15 in Hesperia are back open after crews cleared debris that fell onto lanes during a fire that destroyed the Ranchero Road Bridge overpass.Northbound lanes were opened at 5:15 p.m., while southbound lanes reopened at 11:54 p.m., reports KABC-TV Channel 7.

In the meantime, traffic was routed off the interstate onto local roads to bypass the bridge. Motorists were also advised to use two smaller state highways as alternate routes.

"We still have a lot of work to do to restore traffic," cautioned Ray Wolfe, director of the San Bernardino Associated Governments.

The bridge was intended to carry Ranchero Road over the eight lanes of I-15 about 60 miles northeast of Los Angeles.

The overpass is being built at the northern foot of the approximately 4,200-foot Cajon Pass, one of the few major freeway routes crossing the east-west trending mountain ranges that separate the populous metropolitan areas of Southern California from the expanse of the Mojave and desert cities.

To the north, I-15 stretches 200 miles on to Las Vegas, as well as connecting with Interstate 40, which carries traffic to and from Arizona. To the south, below the other end of Cajon Pass, I-15 connects to a web of freeways serving millions of people from Los Angeles to San Diego.

High-desert commuters had been waiting years for the bridge, the Victor Valley Daily Press reported in January 2013, just before a groundbreaking ceremony for the $60 million, 2-year interchange project in the city of Hesperia.

The bridge had been expected to be completed in early 2015 and the fire is expected to be a 6-month setback, said Michelle Profant, a Caltrans spokeswoman.

The bridge's temporary wooden structures — known as falsework — had been completed and the project was just a few days away from starting to pour concrete, Profant said.

The blaze started when a blowtorch being used to cut metal reinforcing bars accidentally ignited wooden supports of the bridge, the San Bernardino County Fire Department said in a statement.

Arriving firefighters found the fire burning across the entire bridge and saw debris falling onto lanes of the interstate below. Winds gusting up to 35 mph spread the flames and kept the streams of water from reaching deep into the bridge. The location on the interstate limited access to hydrants, requiring water to be hauled in by truck.

One minor smoke inhalation injury was reported.

Copyright 2014 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.