County fire investigators blamed flying molten metal and a lack of safety measures by construction workers for last week's blaze atop the Monte Carlo resort, officials said Thursday.
Workers for Las Vegas-based Union Erectors were using a hand-held torch to cut corrugated steel for a rooftop walkway when the hot metal, called slag, triggered the fast-moving fire that spread across the upper reaches of the 32-story Strip hotel, according to a county statement.
The workers tried to put out the flames with extinguishers before they spread to flammable foam on the facade and sent columns of black smoke into the sky Jan. 25. The flames forced thousands of guests and workers to evacuate the 3,000-room resort, which remained closed Thursday for repairs.
County investigators, with help from the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives, determined the workers failed to take basic safety precautions and did not have the necessary permit for performing "hot work," which includes cutting and welding with a torch.
"We believe this fire could have been prevented had appropriate steps been taken," Fire Chief Steve Smith said in the statement. "It appears that no slag mats were used to catch the molten metal and no fire watch had been posted."
Officials were reviewing the case to determine whether to cite Union Erectors for not obtaining the permit. The misdemeanor carries a maximum $1,000 fine and six-month jail sentence.
Neil Opfer, a construction management professor at the University of Nevada, Las Vegas, said MGM Mirage is "hiring this contractor because they are experienced and do have a track record, but the people out on the job weren't taking the necessary precautions," he said.
He said the workers might have underestimated the flammability of the construction foam used on the hotel facade. Foam products generally burn fast, "like gasoline," he said.
Union Erectors, run by John and Anita Hershberger, has worked on Paris Las Vegas, The Venetian and other Strip resorts, according to its Web site. A woman answering the company's phone Thursday afternoon said John Hershberger was unavailable for comment.
A spokesman for MGM Mirage, which owns the Monte Carlo, said company officials had thought Union Erectors was following county regulations.
"We thought they had a hot work permit, but they didn't," Senior Vice President Alan Feldman said.
Feldman said Tuesday that the workers had filled out hot work permit papers on the morning of Jan. 25 at the Monte Carlo to document the job they were doing that day.
When the Review-Journal requested copies of the paperwork, Feldman responded by e-mail that he could not release it on the advice of corporate attorneys. He then characterized the papers as "internal documents" that the hotel is required by county code to keep on file.
On Thursday, Feldman said Monte Carlo officials never had a copy of the required hot work permit as required by county fire regulations.
"It wasn't done, and it should have been," Feldman said.
Company officials were addressing the problem internally and planned to review the situation with fire and county officials, according to an MGM Mirage statement.
The Union Erectors workers were operating under a general building permit to install window-washing equipment.
Hot work requires a separate permit that spells out several precautions, including using barriers to protect flammable materials and assigning a worker to watch for signs of fire.
The worker on fire watch is not allowed to perform any other duties, Deputy Fire Chief Girard Page said.
Approval for a hot work permit can take from as little as a few weeks to as long as two months, depending on the backlog of requests, Page said.
At the Monte Carlo on Thursday, workers continued repairing and cleaning the damaged areas of the hotel. The work included installation of 8-foot-by-4-foot panels to replace scorched sections of the facade.
MGM Mirage officials have not set a timetable for reopening the resort.
Contact reporter Brian Haynes at email@example.com or (702) 383-0281. Review-Journal writer Joan Whitely contributed to this report.