In this photo provided by the Georgia Ports Authority, Georgia Ports Authority officials and members of the Savannah Fire and Emergency Services speak to the media on the site of a fire over the weekend at the ports Ocean Terminal, Monday, Feb. 10, 2014, in Savannah, Ga. In a press conference today port officials said the cause of the fire wasn't immediately known. (AP Photo/Georgia Ports Authority, Stephen Morton)

A huge fire fueled by burning rubber toppled brick walls and littered twisted metal frames over 113,000 square feet where a warehouse had stood at the Port of Savannah, and fire officials say the hazardous debris is slowing an investigation into the cause.

The blaze began Saturday at the Ocean Terminal near downtown Savannah, sent smoke wafting over the historic district and burned until firefighters extinguished the last flames Sunday morning. No port workers or firefighters were injured though the fire burned so hot that the towering column of black smoke could be seen from miles away.

Investigators on Monday interviewed port employees and inspected the unburned half of the warehouse saved by a cinderblock firewall running through its center. But they had not been able to enter amid the charred debris where the fire began, said Mark Keller, spokesman for Savannah Fire & Emergency Services.

“It may be some time before they get around to being able to dig through some of this to see if they can actually pinpoint where it started and how it started,” Keller told reporters at a news conference in front of the ruined warehouse. “They have to be very careful.”

Otherwise the port terminal had largely resumed normal operations. A cargo ship docked a few hundred feet from the fire site was the only vessel delayed by the blaze, said Griff Lynch, chief operating officer for the Georgia Ports Authority.

The lost warehouse accounted for little of the 200-acre terminal’s 1.4 million square feet of total storage space, and the fire had no impact on Savannah’s container trade that’s handled by another terminal.

“Today it’s business as usual,” Lynch said. “Our truck gates opened up on time, so things are going well.”

Damage estimates weren’t available Monday, but Lynch said port officials may be able to salvage the unburned half of the 226,000-square-foot warehouse. Rebuilding the other half was expected to cost about $7.5 million.

The warehouse that caught fire contained 5,600 tons of raw rubber used in manufacturing. Lynch said the cargo was valued at about $4 million total, but that less than half of it — about 1,800 tons — had burned.

The state fire marshal’s office and the federal Bureau of Alcohol, Tobacco and Firearms were assisting Savannah fire investigators. Keller said the ATF was involved because it has jurisdiction over fires that affect interstate commerce.