The occupant of a Hagerstown apartment set off the sprinkler system while they were using a propane heater to burn bed bugs.
City Fire Marshal Doug DeHaven said in an email that firefighters were called at 10:50 a.m. Monday to an apartment at 509 Lynnehaven Drive.
An investigation determined the occupant was using a propane heater in the kitchen to kill a bed-bug infestation.
DeHaven said high temperatures from the heater caused a single sprinkler head to trip.
He said no one was injured, and building maintenance was called to initiate repairs.
The apartment is part of the Parkview Place Apartments complex near Pangborn Park.
The management office could not be reached for comment.