Thunder Bay firefighters were busy overnight with a house fire at 78 Walkover St.

The fire service says the call came in just before 3 a.m.

Firefighters were able to get the fire under control quickly but there was still extensive damage throughout the house.

It appears the fire started in the basement and spread through main floor.

Nobody was home at the time. Two family cats were rescued.

An investigation into the cause was to begin Monday morning.