Dozens of residents were left without air conditioning as fire fighters battled a multiple-alarm blaze at 44 Queen St. N.
Hamilton fire says, they received the call around 6:30 a.m.
Alectra Utilities responded to the scene and power was cut to the building so that fire crews could extinguish the fire in the hydro vault.
Firefighters made access into the elevators to make sure no one was trapped inside.
A back up generator is currently providing power for lighting in hallways and stairwells as well as one elevator.