Officials from the Fire Marshal's Office, Washington County Sheriff's Department, Maryland State Police, Hagerstown City Police and Long Meadow Vol. Fire Co. collected flyers about the reward from Gosnell and distributed them in the area following the press conference.
Gosnell said he believes the blaze was the work of juveniles because they have been known to hang out at Antietam Creek, which flows behind the warehouse.
Just days before the fire at 1123 Security Road, a blaze at an abandoned home on nearby Needys Lane was deliberately set, Gosnell said.
Investigators have said the Security Road fire was started in the middle section of the four-building warehouse complex.
Gosnell refused to say whether an accelerant was used. An accelerant detecting-dog and his handler were at the scene days after the fire.
The Security Road fire spread rapidly throughout the four buildings, leaving the buildings structurally unstable, officials said.
The warehouse complex will be torn down, according to Paul Prodonovich, director of the Washington County Permits and Inspections Department.
Prodonovich said he is waiting to hear from the Maryland Department of the Environment about the possibility of asbestos in the buildings. He expects to issue a demolition permit this week, he said.
More than 75 area firefighters battled the blaze on Security Road. When firefighters arrived, flames and heavy smoke were coming from the building's roof. The next day firefighters were called to the warehouse to douse a number of spots where the fire rekindled.
The building is owned by the L.G. Mathias family trust and a local roofing company had used the warehouse for storage.
Anyone with information about the fire may call Crime Solvers at 301-733-4141. Callers may remain anonymous.