CHATTANOOGA, TN (CNN) – The four joined the Marines to serve their country, willing to go to dangerous lands out of a sense of duty, idealism and patriotism. And three of them did so, risking their lives in Iraq and Afghanistan.

Ultimately, the men died together in Chattanooga, Tennessee.

The shooter has been identified as Mohammod Youssuf Abdulazeez, 24, of Hixson. Abdulazeez was born in Kuwait. A U.S. official said there was no indication Abdulazeez was on the radar of federal law enforcement before the shootings. The FBI says at this time there’s no evidence he was tied to a terror organization, but they are following all leads.

Multiple sources, including coworkers, told WKRN Thursday night the gunman in the Chattanooga shooting worked in Franklin, Tennessee, at Superior Essex Inc. for the past three months.

One employee told News 2 he called out sick both Monday and Tuesday. It wasn’t clear if he did the same Wednesday or Thursday. The employee also said the Federal Bureau of Investigation showed up to the Franklin plant Thursday night and specifically questioned a man he commuted with to work regularly.

Agents with the TBI told supervisors they didn’t expect to find anything and were there as a precaution.

Members of the Red Cross check in with an officer on Friday morning at the entrance of the reserve center.

The shootings, which only took place minutes apart, began at 10:45 a.m. when the gunman stopped his car and sprayed dozens of bullets at a recruiting center on Lee Highway for all military branches. He then drove to a Navy-Marine training center seven miles away where four Marines were shot dead.

CNN reports the shooting suspect was armed with an AK-47 style weapon and carrying 30-round magazines at the time of the attack according to two law enforcement officials briefed on the investigation.

“Today four of them are gone and one of them is fighting for their life,” said Sen. Bob Corker at a news conference.

Several people have been reported wounded. The Navy confirms a sailor is in critical condition at an area hospital. A Marine recruiter and a Chattanooga police officer was also hurt. The officer, who asked his identity not be released, is said to be doing as well as can be expected.

Authorities have not officially identified the names of the victims, but multiple reports have released the names of two victims.

The India Battery 3rd Battalion 12th Marines posted on their official Facebook page that Marine Gunnery Sgt. Thomas Sullivan, a Massachusetts native, was one of the four marines killed in the shooting.

The second victim has been identified as 21-year-old Skip Wells. He graduated from Marietta, Georgia Sprayberry High School in 2012, according to CNN.

“He never got out of the car, Gina Mule, a server at a local restaurant, told CNN. “He had a big, huge, high-powered rifle, and he was unloading shots right into recruiters.”

A video taken by Jonathen Whitaker in Chattanooga Thursday shows officers reacting to multiple harrowing gunshots.

FBI special agent in charge Ed Reinhold said Abdulazeez had “numerous weapons” but would not give details. The FBI released the following statement on the shootings:

The FBI’s Knoxville Field Office, along with the Chattanooga Police Department and other law enforcement partners, are working jointly to investigate today’s shootings at a military recruitment center and a reserve center in Chattanooga, Tennessee in which four individuals were killed and three injured. The shooter, Mohammod Youssuf Abdulazeez, 24, is also deceased. While it would be premature to speculate on the motives of the shooter at this time, we will conduct a thorough investigation of this tragedy and provide updates as they are available.”

“We are looking at every possible avenue, whether it was terrorism, whether it’s domestic, international, or whether it was a simple criminal act,” Reinhold said.

Within hours of the bloodshed, law officers with guns drawn swarmed what was believed to be Abdulazeez’s house, and two females were led away in handcuffs, according to the Associated Press.

A dozen law enforcement vehicles, including a bomb-squad truck and an open-sided Army green truck carrying armed men, rolled into the Colonial Shores neighborhood of Hixson, and police closed off streets and turned away people trying to reach their homes.

Abdulazeez graduated from the University of Chattanooga in 2012 with a bachelor’s degree in electrical engineering, school spokesman Mike Andrews said. He was a student intern a few years ago at the Tennessee Valley Authority, the federally owned utility that operates power plants and dams across the South. An official cause of death has not been released, but sources said he was killed in a firefight with officers.

In Washington, President Barack Obama pledged a prompt and thorough investigation and said the White House had been in touch with the Pentagon to make sure military installations are being vigilant.

“It is a heartbreaking circumstance for these individuals who served our country with great valor to be killed in this fashion,” he said.

Vice President Joe Biden likewise said: “Their families have already given a lot to the country, and now this.”

Gov. Bill Haslam spoke to the media on two occasions Thursday, each time offering his condolences to the victims. “Tennessee and Chattanooga reacted just as I thought they would, with an outpouring of love,” said Haslam.

Anyone with information on the shooting is asked to call (865) 602-7582.