A fire in the 300 block of Merrill Avenue is thought to be suspicious.

The blaze broke out just aftermidnight Monday morning.

The fire is believed to have started on the main floor.

Fire crews encountered heavy smoke and flames when they first arrived, both inside and outside.

Firefighters were able to knock down the fire using water hoses and brought it quickly under control and prevented it from entering the attic and neighboring homes.

The Thunder Bay Fire and Rescue was then able to make entry in the home and confirmed there was noone in the house at the time of the blaze.

The cause is still under investigation and no injuries were sustained.