A freckled-faced boy brought flowers. A few paid respects by delivering handwritten notes. An Army veteran, with groceries in his car, stopped at the fire station just long enough Tuesday to place a purple bouquet against an outside wall.

All were tokens of condolence in memory of Shane Clifton, a 38-year-old St. Paul firefighter and paramedic who died suddenly Monday night of cardiac arrest.

Clifton had been exercising with his crew around 5 p.m. at Fire Station No. 14, on Snelling Avenue near Laurel Avenue, when he fell sick and collapsed, said St. Paul Fire Chief Tim Butler. Clifton’s colleagues rendered medical aid before he was taken to Regions Hospital, where he died.

“It’s just traumatic,” Butler said Tuesday. “It’s a gut punch to all of us.”

Earlier in his shift, Clifton had participated in three emergency medical calls and two fire calls, the last one just an hour before he collapsed, Butler said.

Autopsy results are pending. But it is possible Clifton’s death was caused by a blocked artery, said Mike Smith, Local 21 union leader.

“St. Paul firefighters lost a great brother, a great friend, a great dad, a great paramedic/firefighter and he will be greatly missed,” Smith said.

Clifton was the 63rd St. Paul firefighter to die in the line of duty and the first since Ray Hain, who passed away in 2009, from blood-borne pathogen exposure he sustained while working on a patient more than a decade earlier.

“This is not unheard of at all, but it’s unfortunate,” Butler said of Clifton’s death. “This guy was young and he was in good shape. … You hope it never happens.”

Those who knew Clifton described him Tuesday as upbeat and always ready to help.

“He was my mentor. He was the only hero that I ever knew,” said Jaime Clifton, of Forest Lake.

Jaime Clifton said that she aspired to be a firefighter, and constantly looked up to her cousin.

“He did what he thought was right,” she said. “He always had a way of looking at the positives.”

Capt. Dennis Jones who sometimes worked with Clifton, said he had a reputation as a hard worker.

“He liked the job,” Jones said. “He liked doing what he was doing.”

Clifton was a U.S. Navy veteran who was named Command Sailor of the Year in 2001 aboard the USS Curtis Wilbur. He worked as an emergency department technician for Unity Hospital in Fridley and Allina EMS before joining the St. Paul Fire Department in 2007.

At the direction of St. Paul Mayor Chris Coleman, flags were lowered to half-staff Tuesday at city facilities in honor of Clifton. Throughout the day, residents, some who knew Clifton and others who did not, left mementos at Station 14.

“Military, police officers and firefighters … they are all a family. They serve the public,” said Lenny Leier, 68, an army veteran, who left the purple bouquet against the station wall.

Kirk Martinson, 43, who lives near the station with his family, didn’t know Clifton, but said the firefighters often run laps around the block and attend the neighborhood’s annual block party.

“They are very much part of the neighborhood so that is sad to hear,” Martinson said.

Bill Sullivan, chair of the board of the St. Paul Fire Foundation, went to Station No. 14 Tuesday to express his condolences.

“This is an extraordinary loss,” he said. “… Firefighters every day put their lives on the line.”

On Sept. 11, the foundation will host a Run or Walk to Remember at Lake Como to memorialize the hundreds of firefighters who lost their lives during 9/11. The event also will honor the St. Paul firefighters who have died in the line of duty, including Clifton, said Mary Kaase, the foundation’s executive director.

Funeral arrangements for Clifton have not yet been announced. He is survived by two daughters.