Investigators from the Division of State Fire Marshal and Portsmouth Fire Department Friday announced they have determined the cause of Tuesday’s Gallia Street fire as arson.

Five people were inside the home when the fire began early morning Tuesday at 3042 Gallia St., in Portsmouth. Three people were injured — one critically.

Brad Nelson suffered major burns and was taken by ambulance to Southern Ohio Medical Center, and, according to Portsmouth Fire Chief Bill Raison, later transported to The Ohio State University Medical Center in Columbus where a hospital spokesman said he was initially listed in critical condition. An update of Nelson’s condition was not available Friday, as the hospital had no record of his admittance.

Assistant Fire Chief Randy Duncan said the Portsmouth Fire Department received the first call at 6:20 a.m. Tuesday. New Boston also reportedly assisted.

First respondent firefighters said the house was 60 percent involved when they arrived.

Firefighter Josh Sherman, standing on the roof, used an axe to take out a portion of the roof to allow fellow firefighters to pour water on the sub-roof area.

Investigators from the State Fire Marshal’s Office were called to examine the scene and conduct interviews with neighbors, witnesses and first responders. Tuesday they announced the cause of the fire has been ruled arson. Smoke detectors were found inside the home, but they reportedly did not activate.

A Blue Ribbon Arson Reward of up to $5,000 is being offered to anyone with information about the person, or persons, responsible for the fire. Anyone with information can call the Division of State Fire Marshal at 1-800-589-2728, or the Portsmouth Fire Department at (740) 353-2660.

RYAN SCOTT OTTNEY can be reached at (740) 353-3101, ext. 235, or e-mail pdtwriter@ryanscottottney

.com.