Authorities say a wind-whipped grass fire that devoured between 10 and 15 acres off Fischer Store Road west of Wimberley Saturday was started by someone mowing a dry field.

The mower “hit a piece of flint or something.” The person doing the mowing, Wimberley Fire Chief Carroll Czichos said, “turned around and looked and about 100 feet behind him was fire.”

Czichos said the fire was reported about 3:30 p.m. and firefighters brought it under control in about five hours. Crews...