Norwalk officials are warning residents after two smoking-related fires in recent weeks.

Investigators today confirmed that a lit cigarette sparked a massive fire at a Norwalk condominium complex over the weekend.

Fire Marshal Glenn Iannaccone says the blaze at the Silver Ridge Condominium Complex started when a resident failed to put out his cigarette. He says the presence of several propane grills on outdoor patios fueled the flames, causing two tanks to explode.

Of the 16 condo units, fire officials say at least eight were completely destroyed.

Officials say that smoking was also the cause of a fire on Maple Avenue one week ago. 20 homeless after Norwalk fire