ST. PETERSBURG -- At Lakewood High School, everyone called him “Mo.” Mohammed Haitham was a track and field star at Lakewood, known for his long legs, big smile and good high jump scores.

After graduating in 2018 he joined the U.S. Navy. He went through boot camp and recently was assigned to flight crew training in Florida. When he surprised his family in St. Petersburg by showing up for Thanksgiving, the 19-year-old didn’t look like a teenager any more.

“He looked like a man all of a sudden,” said Kim Walker, a longtime family friend.

Now Haitham is dead, one of the victims of Friday’s mass shooting at the Naval Air Station Pensacola, according to his mother, Evelyn Brady, and to Lakewood High School principal Erin Savage.

“The commander of his school did call me,” said his mother, herself a Navy veteran who now works for the Veterans’ Administration. “He told me my son did try to stop the shooter.”

PRIOR COVERAGE: Naval base shooter investigated for possible terrorism link.

He was, she said, “an old soul,” often serenading her with Sam Cooke’s posthumous hit A Change Is Gonna Come. He was a popular boy at school. As the word spread Saturday about what happened, his many friends from Lakewood posted numerous testimonials to him on social media.

Anthony Snead, the Lakewood High track coach, said that though the tragedy of Hurricane Katrina brought the family to St. Petersburg from Louisiana, Mo never lost his sense of humor. “He liked to laugh and liked to try to make you laugh.”

“He was an all-around great kid,” said Lakewood journalism teacher Kathleen Ovack Tobin, a former Times reporter. “He was so nice, and a super athlete.”

Mohammed "Mo" Haitham, 19, posted this photo of himself to Facebook Dec. 3. Photo from Facebook.com

FBI officials so far are refusing to confirm the names of any of the victims. A spokesman referred a reporter to the Twitter feed of the agency’s Jacksonville office for more information.

The shooting occurred Friday morning when an aviation student from Saudi Arabia opened fire in a classroom and killed three people, wounding another eight. The shooting, which prompted a massive law enforcement response and base lockdown, ended when a sheriff’s deputy killed the shooter.

The FBI has not released the name of the attacker, but the Associated Press, citing anonymous government sources, said he was Mohammed Saeed Alshamrani, a second lieutenant in the Saudi Air Force. The AP reported that authorities were investigating whether the attack was terrorism-related, and also looking at tweets he may have sent that outline what the author said is a hatred of the United States for crimes against Muslims.

The Pensacola News Journal identified another victim as Joshua Kaleb Watson. He reported to the Pensacola base just two weeks ago and dreamed of being a Navy pilot. He was shot multiple times but was able to tell deputies where the shooter was before he died.

When Haitham paid his surprise visit to his family last month, his mother said, he talked about how much he enjoyed serving in the Navy, and how he was looking forward to graduating from the flight school program Dec. 19.

“He said he was going to get his flight jacket for Christmas,” she said. “Now that’s not going to happen.”

Times senior news researcher Caryn Baird contributed to this report.