INDIANAPOLIS —  The Indianapolis Fire Department responded to a fire at an abandoned apartment building on the city’s east side Wednesday morning.

Crews responded to a call around 4:30 a.m. near East Washington Street and Wallace Ave.

IFD confirms that one firefighter was slightly injured at the scene. Fire investigators are still trying to determine what might have started it.

The roof completely collapsed. At one point, there were at least seven hoses on the fire from the ground level and above the building. Crews were actively fighting it until about 7:30 a.m.

The home next door is damaged on the exterior and the basement is filled with water from crews working to extinguish the flames.

A fire broke out in the same building in June 2021. Since then, the building has been vacant.

Neighbors told FOX59/CBS4 they saw squatters inside the structure within the last week. They left the front door open and broke out some of the front windows.

Arson investigators said they’re going to put in a request to have the property demolished. The cause remains under investigation.