LOS ANGELES (AP) — A freeway construction worker was killed after a 3,000-pound steel beam fell and crushed him as it was being unloaded from a big rig early Thursday, prompting officials to halt work on the four-year, $1 billion project.

The accident happened on a closed off-ramp that is part of a 10-mile widening and carpool project. The work has required two temporary weekend closures of the busy Interstate 405 — one last month and another last year — that became known as Carmageddon I and II.