The NSW racing industry is in mourning after respected trainer Pat Quinn died of a heart attack following a freak accident in a pre-race horse stall at Canterbury.The 63-year-old, who was based at Port Macquarie on the NSW mid-north coast was attending to his horse Insensitive who jammed the trainer into a rail, trapping him until assisted by a strapper.Steward Greg Rudolph said Quinn was unconscious when he left the track in an ambulance on Wednesday and died in transit on the way to St George

The NSW racing industry is in mourning after respected trainer Pat Quinn died of a heart attack following a freak accident in a pre-race horse stall at Canterbury.

The 63-year-old, who was based at Port Macquarie on the NSW mid-north coast was attending to his horse Insensitive who jammed the trainer into a rail, trapping him until assisted by a strapper.

Steward Greg Rudolph said Quinn was unconscious when he left the track in an ambulance on Wednesday and died in transit on the way to St George Hospital.

"My understanding is that he was in cardiac arrest in the ambulance when he left the track and during the course of the afternoon we were advised by paramedics that he'd passed away," Rudolph said.

Quinn's apprentice Allan Chau, who was booked to ride Insensitive, had to be assisted from the jockeys room by officials and was taken to St George Hospital to be with the trainer's family.

Long-time friend and former Ingham employee and now Darley head trainer Peter Snowden was devastated when he heard the news of Quinn's death.

"Racing was his life, he was such a good man. I can't believe this," Snowden said.

Premier trainer Gai Waterhouse echoed Snowden's sentiments.

"If there was good turn he could do for you he always would, he was a lovely man. This is very sad news," Waterhouse said.

Racing NSW chief executive Peter V'landys said Quinn was an outstanding racehorse trainer who did not receive the accolades he deserved.

"Pat was one of the most likeable blokes in racing and was held in very high regard by all his peers," he said. "Our hearts go out to the Quinn family at this terrible time."

Renowned as a great horseman, Quinn trained at Rosehill for several years.

He moved from Rosehill to Hawkesbury in 1990 to pre-train for the Ingham brothers at Belmont Park.

Among the horses Quinn educated was champion Octagonal, the 1996 Sydney triple crown winner.

However, Quinn always held his trainer's licence and after six years working for the Inghams he decided to again train in his own right, initially at Hawkesbury before relocating to Port Macquarie in 2003.

His best horses included multiple stakeswinner Legal Agent who claimed the Missile Stakes-Premiere Stakes double in 1996 and bonny mare Silk And Money who won 12 races and almost $400,000 in prizemoney.

He also prepared Go Mod who dead-heated for third in the 1975 Group One Stradbroke Handicap won by Spedito.

Quinn and wife Gail had two sons Craig and Marc, who is also a trainer. His daughter Tracy is married to Mudgee-based Group One winning trainer Tracey Bartley, who guided Sniper's Bullet to take out the Stradbroke two years ago.