ARVADA, Colo. -- Investigators in Arvada are trying to determine the cause of a fire that sent a woman and two firefighters to area hospitals.

The first calls to 911 came in around 11:18 p.m. Wednesday.

When crews arrived at 68th Avenue and Lamar Street, a woman was leaning out of an upper floor window at the front of the home.

"Heavy smoke and flames were coming from the rear of the home, " said Scott Pribble, the public information officer for the Arvada Fire Protection District.

The woman was brought down a ladder to safety and transported to St. Anthony’s Central Hospital. Her name and condition were not known.

There were reports that there may have been a second person home at the time of the fire, but multiple searches turned up no signs of the person.

A total of 10 fire vehicles and 30 firefighters responded to put out the blaze. Two firefighters were transported to Lutheran Medical Center with minor injuries.