Flames sparked yesterday around 3:40 p.m. at a building on North MacQuesten Parkway where Ad Infinitum Books takes, processes and ships orders.
Crews say there were three separate fires in the building, and they do not appear to be accidental.
Company officials say not that many books were destroyed because most of the collection was in a different location than the fires.
One firefighter was treated for dehydration and smoke inhalation at a hospital and released. One employee working inside the warehouse got out safe.