DENVER (KDVR) — The Denver Fire Department is investigating a fire that injured a firefighter on Monday morning.

The fire was reported around 1:20 a.m. near South Federal Boulevard and West Vassar Avenue at buildings the DFD said were vacant and under construction.

A firefighter was taken to the hospital with minor injuries. No other injuries were reported.

Photo of building after fire (Denver Fire Department)

The fire was under control within an hour and crews worked to hit spots after that.

The cause of the fire is under investigation.