It is likely the Northern Ireland Fire and Rescue Service (NIFRS) will be battling a large fire well into Friday afternoon, a spokesperson has said.
The fire is in the Duncrue Street area of Belfast.
More than 60 firefighters and 13 fire appliances have been involved in battling the blaze.
The expertise of the NIFRS stopped the fire from spreading to three nearby businesses.
The PSNI is at the scene and have closed a road to allow firefighters to manage the emergency operation.
"It is expected that fire crews will be on site dealing with the incident into the afternoon," said a NIFRS spokesperson.
"Fire crews responded quickly to the incident and their early actions have prevented fire spread to three adjoining businesses.
"Firefighters have worked tirelessly throughout the night fighting the fire in difficult conditions, and at the height of the incident a total of 13 fire appliances and more than 60 fire personnel were involved at the scene."
The fire was of such magnitude that smoke is expected to affect the surrounding area for some time.
"Four fire crews are currently in attendance, continuing to deal with the fire," said the spokesperson.
"The high rack shelving and roof in the premises have collapsed, and firefighters are working to extinguish the fire using breathing apparatus and a high volume pump.
"There will continue to be smoke in the area and we would advise the public to keep their windows closed and avoid the area if possible."