Cleveland, OH – Cleveland Police Officer Vu Nguyen died in the line of duty on Friday, four days after he collapsed during a timed run that was part of the department’s K9 handler eligibility process.

Nguyen, 50, collapsed during a mile-and-a-half run in temperatures as high as 93 degrees, The Plain Dealer reported.

“The events were sit-ups and push-ups and a mile-and-a-half run,” Cleveland Police Patrolmen’s Association spokesperson David Medina told WKYC. “At the mile-and-a-half run, at some point, he did collapse.”

Officer Nguyen immediately lost consciousness and was rushed to a local hospital, The Plain Dealer reported.

In the days that followed, Officer Nguyen was intermittently placed on life support, and he began experiencing kidney and liver problems.

Officer Nguyen had been approved for a liver transplant and was flown by emergency helicopter to the Cleveland Clinic on Thursday.

Doctors discovered bleeding on his brain on Friday.

Officer Nguyen, a 25-year law enforcement veteran, had no known pre-existing conditions prior to his collapse, Cleveland Police Patrolmen’s Association President Jeff Follmer said.

“Tonight, our hearts are broken as we ask for your prayers for this hero who has passed away, leaving behind his wife, two daughters, an extensive family and countless friends,” Officer Nguyen and the Cleveland Police Department said in a joint statement on Friday, according to WJW.

“The outpouring of support from the Cleveland community and beyond has been truly amazing and greatly appreciated,” the statement continued. “Patrol Officer Vu Nguyen is greatly loved by his family and by his brothers and sisters in blue.”

Officer Nguyen joined the department in 1998, after having served four years as a detention officer at the city jail, The Plain Dealer reported.

He was assigned to a specialized unit in Cleveland’s Third District at the time of his death, Follmer said.

“He had a great sense of humor, and yet, he understood the responsibility of his job,” La Dolce Vita restaurant owner Terry Tarantino told WJW. “He was a good, solid policeman.”

“He was a lot like an Italian,” the Italian restaurant owner and longtime friend said with a smirk. “He was short, he was tough, and he was fun and funny.”

Tarantino said he once watched Officer Nguyen – dressed in full uniform – has he handed out tissues to Chicago fans on a Cleveland street corner.

“He was standing on the street…he was passing out tissues for people to cry in,” Tarantino recalled through laughter. “And he was asking all the people from Chicago, ‘cause they had their Chicago garb on, ‘Would you like a tissue?’”

In 2015, Officer Nguyen and his partner made headlines after they helped save the life of a 14-month-old girl who stopped breathing after a seizure, The Plain Dealer reported.

Without the lifesaving care they administered to the toddler until emergency medical crews arrived, she would have died, officials said at the time.

“We basically did our job,” Officer Nguyen told WKYC shortly after the incident. “It’s what we’re out here for is just to protect and serve and do what we can to save that baby.”

On Saturday and Sunday, three young boys in Brooklyn, Ohio opened a lemonade stand to raise money to help Officer Nguyen’s family in the wake of their loss, WJW reported.

The boys’ mother said that first responders are the children’s heroes and that they wanted to do something to help. The boys earned over $5,000 from their stand, and received hugs and Commander’s Commendation coins from the officers who came to accept their donation.

“Your act of kindness does not go unnoticed,” one of the officers told the boys. “As you grow up, you’re going to see pictures and remember back and say, ‘Hey, we did something great.’”

Officer Nguyen’s coworkers also held a garage sale on Saturday, and donated the proceeds to the fallen hero’s family, WOIO reported.

Officer Nguyen leaves behind his wife, Holli, and his daughters, Kayla and Maya, according to his obituary.

He also has 14 siblings, and many cousins, nieces, nephews and friends, WKYC reported.

Officer Nguyen will be laid to rest on Thursday.

Our thoughts and prayers are with the family of Cleveland Police Officer Vu Nguyen, both blood and blue. Thank you for your service.

Rest easy, hero. We’ll hold the line from here.