DE PERE, Wis. (WFRV) — Crews responded to a structure fire at 749 Elm Street in the City of De Pere Thursday at 5:22 P.M.

Upon arrival, the crews found smoke and charring on the upper unit exterior of the 2-story duplex.

The fire was extinguished within minutes and all occupants had been self-evacuated before they arrived.

It was later discovered that a passerby had observed the smoke and stopped to alert the residents (a family consisting of two adults and three children) who were inside asleep at the time of the fire.

After investigation, it was determined that the cause of the fire was the careless use of smoking materials.

There were no firefighter of civilian injuries reported.

The estimated damage to the structure is approximately $5,000.

De Pere Fire Rescue Department would like to remind everyone that smoking materials are the leading cause of injuries and fire deaths.

Before you throw away butts and ashes, make sure they are out, and dousing in water or sand is the best way to do that.