Marines killed in Chattanooga last week diverted the gunman from a larger group of people to avoid more fatalities, officials said in a press conference Wednesday. “This could have been a lot worse,” an official told The New York Times. “It could have been a horrible, horrible massacre—so much worse.” Marine Gunnery Sgt. Thomas Sullivan, Staff Sgt. David Wyatt, Sgt. Carson Holmquist, and Lance Cpl. Squire Wells were killed in the July 16 attack, as was Naval Petty Officer Randall Smith. Officials at the press conference also said that a Marine noticed heavily armed Muhammad Abdulazeez approaching the building and fired at Abdulazeez before he made it inside. The FBI’s special agent on the ground said it is “too early” to determine whether Abdulazeez had been radicalized, but that the bureau is treating him as “a homegrown violent extremist” who likely acted alone. Officials would not comment on where the weapons used were purchased, but said that all of the servicemen appeared to be killed with the same gun.