A 62-year-old retiree who took part in The Straits Times Run in the City on July 16 died on Monday night.

Mr Freddie Lim suffered a heart attack on July 16 and was warded at Tan Tock Seng Hospital, where he had been fighting for his life.

He was taking part in the 10km category run when he collapsed at 7.43am in Republic Avenue, just past the 5km mark.

ST Run race organiser Infinitus Productions said a medic attended to him one minute after his fall.

The medic started cardiopulmonary resuscitation immediately after assessing that Mr Lim had no pulse, and managed to resuscitate him.

Mr Lim was put into an ambulance that was stationed on-site at 7.45am, but had to be resuscitated again while in the vehicle, before reaching Tan Tock Seng Hospital at 7.56am.

His son Kenneth told The Straits Times that his family was by his bedside when he died just before 10pm on Monday.

The younger Mr Lim said his father was a very active person who would go on 6km to 7km runs about two to three times a week. He would also swim daily. "He went doing what he loved," said Mr Lim, 38, a psychologist.

His father, a former insurance broker, took part in full marathons during his younger years. But he preferred to run just 10km races of late. He also took part in the 2014 ST Run at the Hub.

Mr Freddie Lim leaves behind his wife, Judy, children Kenneth and Kristy, and grandchildren Charlotte and Charmaine.

The family paid tribute to Mr Lim in an obituary in ST that read: "His sixty-two years had been bursting at the seams with laughter; exploring the world; lingering over cups of coffee; breaking rules and making his own, followed by breaking his own rules to make new ones; challenging himself and others; under-promising and over-delivering in his professional life; making waves and pushing boundaries; dispensing words of wisdom; planning three steps ahead with spontaneity."

Said Mr Kenneth Lim: "Since his retirement (in 2015), he has been spending a lot of time with the family. He and my mother were in Europe earlier this year, we went to Perth in June, and my mom and him were planning a cruise to mark their 40th wedding anniversary in November."

Said Mr Warren Fernandez, ST editor and editor-in-chief of Singapore Press Holdings' English/ Malay/Tamil Media group: "We are greatly saddened by this news and our hearts go out to his family.

"Safety is always top of mind when we organise these events, as we want all our runners to enjoy themselves and go home safely to their families. Sadly, this was not to be in this case.

"I've asked our team to do all we can to assist the family at this difficult time."

Mr Lim's wake will be held at Mount Vernon Sanctuary from noon today until Friday afternoon.