ST. CHARLES COUNTY • Investigators believe discarded cigarette butts started a fire early this morning that destroyed a home in St. Charles County.

No one was injured in the blaze that was reported about 1 a.m. at 538 Highfield Drive. Assistant Chief Scott Freitag said five people escaped the house because of two children who acted quickly.

Freitag said the homeowners' grandchildren saw smoke and fire coming from an interior door to the garage. They alerted their sleeping grandparents, he said. The grandparents were able to get their teenage daughter out of the home's basement before flames cut off her access to the stairs.

Freitag did not know the occupants' ages, but he estimated the grandchildren were between 10 and 12 years old.

"Had it not been for the grandchildren being up and waking the grandparents, the teenage girl in the basement could have been trapped," Freitag said.

He said two cats were lost in the fire.

The accidental fire started in the garage, and cigarette butts thrown in a plastic trash can probably caused it, Freitag said. Two cars parked inside the garage and a third parked just outside were destroyed.

Heat from the flames also melted siding on a neighbor's home and may have damaged an air conditioning unit, Freitag said. Total losses were estimated at more than $250,000.