PORTLAND — Damage from Thursday’s fire at the former Jordan’s Meats property is so severe that investigators can’t determine the cause, the city said in a press release today.

But it’s likely that the fire was accidental and related to demolition activities under way at the site, the city said.

Fire Chief Fred Lamontagne was scheduled to speak at a press conference at noon, where he will discuss the investigation and next steps for the heavily damaged building on the block bounded by Fore, Franklin, Middle and India streets.

More than 100 firefigters turned out to battle the fire, which broke out around 1:30 p.m. and sent a thick plume of smoke over the peninsula that attracted hundreds of onlookers.

There were no injuries.

The fomer meat packing plant was under demolition to make way for a hotel and condominium project, a $17 million project by Old Port Hospitality LLC.