Survivors of Maine’s deadliest mass shooting and relatives of victims are suing the federal government, alleging that the U.S. Army could and should have stopped one of its reservists from carrying out what they call “one of the most preventable mass tragedies in American history.

One hundred plaintiffs are seeking accountability from the Army, the Department of Defense and Keller Army Hospital for allegedly violating their own "policies, regulations and orders" intended to protect the public from soldiers with mental illness.