The January 30 blaze engulfed the Playland's Castaway Cove arcade and offices, Hamburger Construction Company restaurant and Dairy Queen located on the boardwalk.
On Monday, officials announced that the accidental fire was caused by an undetermined electrical source near the front of the building.
SEE ALSO: 4-alarm fire erupts at boardwalk in Ocean City, damages amusement park
Video from scene of Ocean City Boardwalk fire
Playland Castaway Cove says it was storing some ride parts in the building for the winter. No one was inside when the fire started, and the city says no one was hurt.
"If anybody knows us, we're going to come back with something bigger, that's for sure," said Brian Hartley, vice president of Playland's Castaway Cove.
Hartley tells Action News that the arcade and offices burned down, but the rest of the park was untouched and will reopen this summer.
Federal and local investigators were able to use a pattern of fire alarms, eyewitness accounts, photos and videos, a detailed excavation of the site and examination of forensic evidence to determine the cause and area of origin for the fire.
Chopper 6 shows fire damage to Ocean City Boardwalk