Hundreds of victims of the October mass shooting in Las Vegas are suing over the attack, arguing that the owners of the hotel the gunman used to stage the assault and the organizers of the festival he targeted failed to adequately protect them.

In five lawsuits filed on Monday, lawyers representing more than 450 victims of the ordeal sued MGM Resorts International, which owns the Mandalay Bay hotel and the festival venue, as well as Live Nation Entertainment, the concert promoter. They also sued the estate of the gunman, Stephen Paddock, whose attack ended with 58 concertgoers dead and about 500 more wounded.

The filings are the latest in a series of lawsuits alleging that the businesses, and others, contributed to the severity of the attack in avoidable ways. The plaintiffs in the lawsuits filed on Monday include victims of gunshot wounds and trampling as well as those suffering from post-traumatic stress.

“Each one of them has a unique story,” said Muhammad Aziz, a Houston-based personal injury lawyer who is among those representing the victims.