Overland Park, KS- A natural gas line that fed residential fireplaces probably caused a blaze at an Overland Park apartment complex Tuesday, a Fire Department official said.

“Gas from that line somehow escaped and found an ignition source in a furnace in one of the apartments, causing an explosion and fire,” Jason Rhodes, Overland Park Fire Department spokesman, said Wednesday.

The fire injured several people, one of them seriously.

Investigators spent much of Wednesday making the building at the Metcalf 56 Townhomes complex structurally sound enough to allow an interior inspection, Rhodes said.

Firefighters responded to an alarm just after noon Tuesday in the 5600 block of Floyd Street and found a large fire in the back of a three-story apartment building.

Emergency medical personnel transported one person with burn injuries, which Rhodes described as “significant,” to a hospital. That person’s condition was not available Wednesday.

One police officer was taken to a hospital with minor smoke inhalation. That officer was released later Tuesday, said Gary Mason, Overland Park police spokesman. Several apartment residents were treated at the scene for smoke inhalation.

The fire damaged at least 10 apartment units, Rhodes said, and smoke damaged six more. It took two hours for firefighters from four Johnson County departments to bring the blaze under control.

Fire officials don’t believe the complex had any unresolved code issues, Rhodes said.

Red Cross personnel helped 29 people affected by the fire. The assistance included allowances for food, clothing, laundry and prescription medications, said Duane Hallock, regional communications director for the American Red Cross in Kansas City.

Four families spent the night in a motel, Hallock added.