HAYWARD, CALIFORNIA — A major explosion Thursday morning leveled multiple homes, injured several people, and forced the shutdown of a major freeway after a construction crew struck an underground gas line, according to fire officials, witnesses, and PG&E.

The incident occurred in the 800 block of Lewelling Boulevard, where a third-party construction crew was working on a public improvement project.

PG&E spokesperson Jason King confirmed that the crew accidentally damaged a buried gas line at approximately 7:35 a.m. while excavating in the area.

King provided a timeline of events, noting that PG&E crews were able to stop the gas flow at 9:35 a.m., but just three minutes later—at 9:38 a.m.—a violent explosion erupted, triggering a fast-moving fire that swept through nearby structures.

A slow-motion video circulating online appears to show the moment the blast sent debris flying and violently shook an excavator, with the operator struck by falling roof material.

The explosion destroyed at least two homes and a workshop or outbuilding, sending thick plumes of smoke into the sky.

Alameda County Fire officials said six people were transported to area hospitals, and additional residents were evaluated at the scene.

As of 1:30 p.m., Fire Captain Ryan Nishimoto reported that two residents remain unaccounted for; however, their vehicles were not found at home, leading authorities to believe they may have been at work or school during the incident.

During firefighting operations, crews reported feeling “electric shocks” near the burning structures, forcing firefighters to temporarily withdraw until the area was deemed safer.

In total, 75 Alameda County firefighters responded to the third-alarm fire.

The blast prompted the California Highway Patrol to close portions of Interstate 238 between East 14th Street and Lewelling Boulevard, as well as segments between Mission and Paradise boulevards, to protect the public and allow emergency crews access to the scene.

Alameda County Sheriff’s Office spokesperson Roberto Morales stated that deputies arrived within two minutes of the first emergency call, immediately evacuating residents from hazardous areas and assisting firefighters.

The construction work taking place is part of the East Lewelling Boulevard improvement project, which aims to widen sidewalks, install new bike lanes, add high-visibility crosswalks, and improve safety at railroad crossings.

Investigators are now working to determine the full circumstances surrounding the gas line strike and subsequent explosion.

Authorities have not yet released information regarding the condition of the injured victims.