Crews battled three fires late Wednesday and early Thursday in Toledo's east, north, and central areas, authorities said.
There were no injuries, according to the Toledo fire department.
Occupants escaped unhurt before fire crews arrived about 9:40 p.m. at a two-story duplex at 534 Starr Ave. and found flames in the upper-level bedroom. Firefighters extinguished the blaze in about five minutes, authorities said.
Fires at vacant houses at 3349 Franklin Ave. in North Toledo and at 1389 Grand Ave. in the central city were reported at 2:39 a.m. and 4:13 a.m. respectively.
It took the crews about 20 minutes to knock down the flames at the two-story wood frame house at Franklin and about two hours to extinguish the blaze at a single-story wood frame house on Grand, the remains of which was later scheduled for demolition, according to the department.
The causes of the fires were under investigation. There were no damage estimates available.