A small fire started underneath concrete steps at the Knollwood Townhouses apartment complex Saturday morning.
Firefighters cut into the floor inside the doorway of the apartment in an attempt to find the source of the smoke. It was coming from underneath the outdoor concrete steps that lead up to the front door of apartment K105.
After breaking into the steps with sledgehammers, firefighters with the Rapid City Fire Department discovered a large amount of dry straw smoldering inside the steps.
Battalion Chief Tim Daly said the straw is used for insulation. He said he has never seen the practice, but he was told by a fellow firefighter that it is not uncommon. Daly said cracks in the concrete may have allowed something hot to reach the straw.
There were several cigarette butts on the ground beside the steps.
The apartment manager was on scene and spoke to the firefighters. She declined to comment or identify herself to the Journal.
Residents in the two adjoining apartments were evacuated and allowed to return to their homes after firefighters determined there was no risk.
Neighbors stood outside their apartments watching the scene as the group of firemen swung sledgehammers to break the concrete steps and pull out mounds of straw, some of which was black and smoldering.
A jackhammer was eventually brought in to allow firefighters to completely remove the steps and the straw inside.
Daly said the cause of the fire is still under investigation.