WINDSOR – Investigators now believe a fire in Windsor that claimed the life of a tenant was intentionally set.

Windsor fire fighters rushed to the building at Ouellette Avenue and Hanna Street around 8 p.m. on Thursday to find heavy smoke coming from a ground floor unit facing Dufferin Street.

Chief Fire Prevention Officer John Lee confirms fire fighters pulled a man from an apartment.

"Through our efforts, we tried to revive him, we were unsuccessful and the gentleman has passed away."

No name has been released, but it's believed the man was in his 40's.

Michael Lukas lives in the building. He tells CTV News he tried to help.

"Banged on the door. I could hear the guy hollering," says Lukas. "I went down the hallway, had my eyes closed, my lungs full. We couldn't stay any longer, We had to get out of there."

The man is the fourth person to die in a fire in Windsor this year.

The cause of the first three fires was careless smoking.

But investigators say Thursday's fire was intentionally set and Windsor police are now investigating, but won't provide more details on why.

Damage from the fire is estimated at $100,000.

Four people and two dogs were displaced.