The Ontario Fire Marshal is investigating after a house fire in Bolton early Sunday morning.

Fire crews were called to Connaught Crescent after 12:30 a.m. and when they arrived they found a fire in the roof of one home which then spread to an adjacent house.

Crews were able to put out the fire and nobody was injured.

Damage is estimated at $600,000.

The fire is not considered suspicious and the OFM has been called in due to the damage to both houses.