Four Colorado Springs firefighters sustained minor injuries early Sunday as they battled a two-alarm blaze that left four people displaced, fire officials said.

At about 2:20 a.m. Sunday, crews were dispatched to a structure fire in the 1200 block of Tonka Avenue in the city’s west end. While en route to the scene, engine crew members reportedly could see a glow from a fire in the distance.

As crews arrived at the scene, they saw flames coming from all the windows of the home, according to a social media post from CSFD. As they searched the interior of the home, one firefighter fell through a split-level staircase. The injured firefighter was evacuated and treated at the scene.

Below-freezing temperatures, exacerbated by winds, caused some of the firefighting equipment to freeze, and three additional firefighters sustained minor injuries from falling or slipping on ice, but CSFD crews managed to knock down the bulk of the fire by 3 a.m., officials said.

Two adults, a child and an infant were displaced by the blaze. A dog was unaccounted for as of Sunday morning.

No other injuries were reported, and the cause of the fire is under investigation.