MGM Resorts International has sued hundreds of victims of the deadliest mass shooting in modern U.S. history in a bid to avoid liability for the gunfire that rained down from its Mandalay Bay casino-resort in Las Vegas.

The company argues in lawsuits filed Friday in Nevada and California that it has "no liability of any kind" to survivors or families of slain victims under a federal law enacted after the attacks on Sept. 11, 2001.

The lawsuits target victims who have sued the company and voluntarily dropped their claims or have threatened to sue after a gunman shattered the windows of his Mandalay Bay suite and fired on a crowd gathered below for a country music festival.

High-stakes gambler Stephen Paddock killed 58 people and injured hundreds more last year before killing himself. Victims with active lawsuits against MGM don't face the company's legal claim.

MGM says the 2002 law limits liabilities when a company or group uses services certified by the U.S. Department of Homeland Security and mass attacks occur. The company says it is not liable because its security vendor for the concert, Contemporary Services Corp., was federally certified at the time of the Oct. 1 shooting.

MGM claims the victims — through actual and threatened lawsuits — have implicated CSC's services because they involve concert security, including training, emergency response and evacuation.

MGM's lawsuits target victims of the shooting who have sued the company and voluntarily dropped their claims or have threatened to sue. (Lucy Nicholson/Reuters)

'They remained in the line of fire'

"If defendants were injured by Paddock's assault, as they allege, they were inevitably injured both because Paddock fired from his window and because they remained in the line of fire at the concert. Such claims inevitably implicate security at the concert — and may result in loss to CSC," according to the MGM lawsuits.

The company wants a court to declare that the U.S. law "precludes any finding of liability" against MGM "for any claim for injuries arising out of or related to Paddock's mass attack."

CSC's general counsel, James Service, did not immediately return a call seeking comment.

Lawyer Robert Eglet, who represents victims in a lawsuit pending in federal court in Nevada, decried the casino-operator's move.

"MGM has done something that in over 30 years of practice is the most outrageous thing I have ever seen," Eglet said. "They have sued the families of victims while they're still grieving over their loved ones."

Four Canadians who were attending the targeted outdoor music festival died in the shootings: Jordan McIldoon, 23, of Maple Ridge, B.C., Jessica Klymchuk, 34, of Valleyview, Alta., Calla Medig, 28, of Edmonton, and Tara Roe, 34, of Okotoks, Alta.

Brandon and Melissa Vanderloo of Lindsay, Ont., were among those in the crowd of 20,000 when the gunman started firing from the 32nd floor window of the hotel. They escaped by running and hiding under bleachers.

At least six other Canadians were injured in the attack, including two women from Manitoba, two men from Saskatchewan, a man from Victoria and a man from Calgary.