A deadly house fire in Colorado Springs has left to young children dead. The fire started just before two a.m. Friday morning on Undimmed Circle. That’s in the Village Seven neighborhood.

An 11-year-old boy and a 3-year-old girl died in the blaze. A 6-year-old girl is in critical condition at Memorial Hospital. The children’s father, who has been identified as 32-year-old Timothy Nichols is in critical condition at University Hospital in Denver.

Captain Randy Royal of the Colorado Springs Fire Department says, “When we arrived at the scene, we found heavy fire and smoke conditions. We immediately called for 2nd alarm.”

The father was outside the home, but his three children were still inside. Investigators say the 11-year-old boy died at the scene. The rest of the family was immediately tranported to the hospital.

But Investigators are still trying to piece together what caused the blaze. They did find a smoke detector on the bottom floor of the home, but there weren’t any batteries inside. Firefighters say that’s the worst part of their job, “Anytime we deal with any of these incidents, it’s hard on the guys. But when they deadl with kids especially, it’s rough.”

A working smoke alarm could have saved precious time and possibly lives in this fire. Nearly half of all residential fires, and three fifths of residential fatalities occur in homes with no smoke detectors.

There are steps you can take to ensure your smoke alarms work properly in the event of a fire. Fire officials recommend testing them once a month. Most detectors have a button on them to conduct a test. Batteries in detectors should be changed twice a year. A good time to do that is when time changes occur in the fall and the spring. And always make sure smoke detectors that run on electricity have a battery back up in place.