AP Photo/Mark Zaleski
"While I cannot share specific details about what happened that morning, our Marines reacted the way you would expect - rapidly going from room to room. They got their fellow Marines to safety," Maj. Gen. Paul Brier, commanding general of the 4th Marine Division, said during a press conference on Wednesday.
"Once they got them to safety, some willingly ran back into the fight," he added.
The FBI has said that four Marines - Marines Gunnery Sgt. Thomas Sullivan, Staff Sgt. David Wyatt, Sgt. Carson Holmquist and Lance Cpl. Squire Wells - were $4 by 24-year-old Muhammad Youssef Abdulazeez last Thursday when he opened fire on two military facilities in Chattanooga, Tennessee.
Navy Petty Officer 2nd Class Randall Smith was shot and died later from his injuries.
Wielding a semiautomatic derivative of an AK-47 assault rifle, Abdulazeez attacked a military recruitment office - shooting through the office's front door from his car, injuring no one - before driving roughly six miles to a naval reserve center and crashing through its gates.
AP Photo/John Bazemore
"This could have been a lot worse," an official who wished to remain anonymous $4. "It could have been a horrible, horrible massacre - so much worse."
Officers reportedly began firing at the shooter as soon as he crashed through the reserve center's gates, but he was able to enter the reserve center where he shot and "mortally wounded" a sailor before exiting through the back and killing four Marines in the center's gated motor-pool area.
The shooter was eventually "neutralized" by Chattanooga police officers, an FBI agent told reporters, and all evidence suggests he acted alone.
Officials are treating the shooting as an act of domestic terrorism, and are investigating the $4 of the Kuwait-born Abdulazeez, who was a naturalized US citizen and lived most of his life in Chattanooga.
"When history records what happened in Chattanooga last week, it won't be remembered for the heinous actions of one individual," Brier said. "The legacy of that day is one of valor."