OMAHA, Neb. (AP) — Omaha firefighters say freezing temperatures created challenges, like frozen equipment, while battling a fire after an explosion that injured two people.

The fire department responded to reports of an explosion around 2:50 p.m. Saturday in the city’s Old Market district. A restaurant and some apartments were damaged in the explosion, which remains under investigation.

Battalion Chief Matt Carmichael said Wednesday that he had to rotate crews more often than usual because their masks kept freezing, making it difficult to breathe and see.

Crews worked in conditions that included a wind chill that dropped to 25 degrees below zero. A firefighter broke his hand after slipping on ice.

Authorities think a company working on a fiber optic project may have struck a natural gas line, leaking gas into the area before the blast.