The fire started about 10:30 p.m. at a building just off U.S. 501 near the closed The Pottery at Waccamaw.
Nobody was inside the building during the fire, and no firefighters were injured while fighting it.
On Friday afternoon, Horry County Fire Rescue crews were on the scene going through the charred remains of the building.
Officials don't yet know how the fire started, but they think it's suspicious, said Horry County Fire Rescue Battalion Chief Melissa Hilts.
The building had no working utilities or electricity.
Flames were visible for miles Thursday as the building burned, and more than 60 firefighters were fighting the blaze.
Most of the firefighters were from Horry County Fire Rescue, but the Myrtle Beach Fire Department sent one truck to help, Lt. Dan Walker said.
There is no timetable to finish the investigation. The State Law Enforcement Division recently released the results of an investigation into a May 7 fire that destroyed a condominium several hundred yards from the scene of Thursday's fire.
Lt. Mike Brown of SLED said the cause of the fire was undetermined. That fire destroyed a three-story, nine-unit condominium on River Oaks golf course.
There were people living in the condominium at the time, but everyone got out and managed to avoid injury; several cats were injured.
SLED was called in to investigate that fire because of the high dollar amount of damage. Hilts said SLED has not been called in to investigate this fire and doesn't know whether it will be.
