Photo courtesy of Chatham-Kent Fire and Emergency Services.

Fire investigators have closed the book on an apartment fire in Thamesville, pegging the blame on careless smoking.

Crews arrived at the Victoria Street property just before 10:30 yesterday morning and authorities say flames could be seen from the front windows and doors.

Fire fighters were able to contain the blaze to the initial unit. The property owner was treated for smoke inhalation at the scene, officials say all of the tenants were able to escape unharmed.

Investigators have listed the official cause as smoking near combustibles on a mattress.

Damage is estimated at $100,000.