Workers on the roof of the Monte Carlo Hotel and Casino in Las Vegas started last week’s roof fire with a hand-held metal cutting torch. According to fire officials, the contractor employing those workers did not have the appropriate permits. The Monte Carlo Casino Fire—which destroyed a large section of the roof-top and required full evacuation of its 5,000 guests and 900 workers—was caused by flying molten metal emanating from the hand-held cutting torch.

According to Deputy Fire Chief Girard Page, if the contracting company—Union Erectors, LLC—had gone through the appropriate channels and applied for a permit, it would have been advised on how to perform the work safely and likely been approved in four to five weeks. “It does take time and effort, but it’s not that difficult,” Page added. Officials are reviewing whether to cite Union Erectors, which could result in fines of $1,000 and up to six months in jail per citation, a misdemeanor.

The melting steel sparked a fire on the southwest corner of the main facade of the roof of the 3,002-room, 32-story Monte Carlo Hotel and Casino on Friday morning. The flames rapidly spread, burning through a foam-like material on the façade of the Monte Carlo Hotel and Casino. When the fire reached the foam, sections melted off, streaming flaming debris on the Las Vegas Strip, causing small fires on the buildings’ lower sections. While there were no fatalities, 17 people were injured and taken to area hospitals with most injuries resulting from smoke inhalation or fleeing.

About 120 fire fighters contained the three-alarm fire; construction workers using four hand-held extinguishers failed to put the blaze out. Because fire ladders were unable to reach the roof of a 32-story building, crews fought the fire from the hotel’s windows.

The Monte Carlo Hotel and Casino remained closed Thursday and casino operator MGM Mirage Inc. confirmed that the paperwork for the metal work that caused the fire “did not meet our corporate standards” and said in a statement that the situation was “being immediately addressed.” Meanwhile, Union Erectors had only a county permit to install window-washing equipment and did not have paperwork allowing them to work with torches.

The fire at the Monte Carlo Hotel and Casino was the first of two roof fires within a week at U.S. gambling resorts. A fire on Tuesday at the Great Cedar Hotel at Foxwoods Resort Casino in Mashantucket, CN., injured none but forced guests to evacuate. In that fire, a device meant to keep pipes from freezing malfunctioned.

The Monte Carlo Hotel and Casino opened June 1996 and is on the Las Vegas Strip not far from the scene of Nevada’s deadliest fire when, in November 1980, a blaze killed 87 people at the old MGM Grand hotel and led to strict fire codes in Las Vegas resorts.