Thunder Bay Fire and Rescue officials are investigating the second vacant building fire in a south-side neighbourhood in less than a week.

A view of the rear of the building at 112 Finlayson St., where the fire broke out on Saturday. (Nicole Ireland/CBC)

Firefighters battled a blaze at 112 Finlayson St., for about three hours on Saturday morning.

No one was living in the house.

Neighbour Gordon Rummerfield said he and his wife were sleeping and awoke to a loud noise.

A boarder in their home told them there was a fire across the street.

"The flames were about three (or) four feet high above the roof," Rummerfield said.

The house is just blocks away from a vacant Cumming Street apartment building that was consumed by fire on Feb. 17.

Thunder Bay Fire platoon chief Dan Hyvarinen told CBC he couldn't comment on whether or not officials suspect any connection between the two incidents, because both are currently under investigation.