LEWISTON, Maine (AP) — Lawyers representing 100 survivors and family members of victims of the deadliest shooting in Maine history have begun the formal process of suing the Army and an Army hospital for failing to act to stop the reservist responsible for the tragedy, attorneys announced Tuesday.

The individual notices of claim say the Army was aware of the reservist’s mental health decline that left him paranoid, delusional and expressing homicidal ideations, producing a “hit list” of those he wanted to attack.

“It is difficult to conceive of a case in which Army personnel could have more warning signs and opportunities to intervene to prevent a service member from committing a mass shooting than what happened in the case of Army Reservist Robert Card,” lawyers wrote in their notices mailed Friday.

The notices of claim by four law firms are a required step in suing the federal government. The Army will have six months to determine whether to respond, after which a lawsuit may be filed.

Eighteen people were killed when the 40-year-old Card opened fire at two locations he’d frequented — a bowling alley and a cornhole league hosted by a bar and grill — on Oct. 25, 2023. Another 13 people were injured. Card was found dead two days later from a self-inflicted gunshot wound.

An independent commission appointed by Maine’s governor concluded that there were ample opportunities to intervene by both civilian law enforcement and the Army. For now, lawyers for victims and family and friends who suffered loss are focusing on the Army, and not a private hospital that treated Card or civilian law enforcement.

The Department of Defense, U.S. Army and Army Keller Hospital “broke its promises, failed to act reasonably, violated its own polices and procedures and disregarded directives and orders,” the claim said.

In September 2023, when Card threatened to “shoot up” an armory and his friend warned of “a mass shooting,” the Army failed to provide critical background about two doctors recommending that Card not have access to weapons when it requested that local law enforcement officers check on his well being. Card’s commanding officer even downplayed the threat by undercutting the credibility of the soldier who issued the warning, and by declining to share all information at his disposal, the claims said.

Cynthia Young, whose husband William and 14-year-old son Aaron were killed at the bowling alley, said in a statement that pain and trauma never goes away. “As terrible as the shooting was it’s even more tragic that there were many opportunities to prevent this and they were not taken,” she added.

The filings said there may have been a time when mass shootings were so rare that they couldn’t be predicted but “that has not been true in America for decades.”

“Mass shootings, like what happened in Lewiston, are an epidemic in America. Consequently, those in positions of responsibility and authority are required to appreciate the warning signs and behaviors that telegraph the risk of mass violence, take them seriously, and act to prevent their occurrence,” the claims said.