Crews responded to a fire at a home on the 2400 block of N. 5th Street just after 9 a.m. Thursday.
Officials say it involved three homes, one duplex and one part of a neighboring duplex.
Units from Steelton, Susquehanna Township, Swatara Township, Penbrook, DLA Susquehanna, Life Team EMS and the West Shore Bureau of Fire responded to the two-alarm blaze.
The fire was brought under control around 10 a.m. but units remained on scene until after noon.
The units were abandoned and were supposed to be vacant however authorities believe people were occupying the units. Officials say the total estimated loss is approximately $115,000.
The cause of the fire is under investigation.
Two firefighters were treated for minor injuries.