A task force formed to probe a series of arsons on the Charleston peninsula is trying to locate a witness to a blaze Saturday at 54 Vanderhorst St.

A white man about 22 years old knocked on the door of the residence about 4 a.m. to alert occupants of the fire. The fire started in a plastic recycling bin in the breezeway area of the residence, and with the assistance of the man, the resident quickly put the fire out.

Charleston police and fire departments were not notified of the incident until approximately eight hours after later, Mark R. Ruppel, public information officer for the fire department said Tuesday.

He said the man is considered a witness and not a suspect, and the Peninsula Fire Investigation Task Force is hoping he will come forward.

A composite sketch is being distributed in hopes someone can help authorities find the man, he said.

The individual is described is about 5 feet, 10 inches tall, with a medium build, blond hair and blue eyes, and was last seen wearing a gray sweater and white tennis shoes. He is asked to contact the police or fire officials at 843-577-7434.

The Peninsula Arson Task Force is also reminding citizens in the area to please report any suspicious activity or fire immediately to 911.