Kilmarnock's game against Hibernian at Rugby Park has been abandoned due to an off-field incident, the club have announced.
Police confirmed that a fan had suffered "a possible heart attack" causing the Scottish Premier League game to be called off shortly after half time.
An ambulance drove pitchside 10 minutes later with the supporter then being taken away to Crosshouse hospital and the match called off, 26 minutes after it had been stopped. The man later died in hospital.
The match was tied at 1-1 after Kris Boyd had scored for Kilmarnock in the 31st to cancel out Alex Harris' opener for the visitors.
Inspector Sean Mangan, the match commander, said: "A supporter was taken ill in the East Stand, possibly a Kilmarnock fan. Ambulance staff and club doctors have been assisting with that male, he has now gone off to the hospital in the ambulance.
"It is looking like a possible suspected heart attack but of course I am not a medical professional to absolutely tell you that is the case but it is certainly serious enough that the club, in conjunction with the police and the SPL fourth official, have decided out of respect for the male and possibly his family that the match would be abandoned."
Kilmarnock manager Kenny Shiels insisted the game had to be abandoned out of respect.
In March 2012, Killie's League Cup winning celebrations following their victory over Celtic at Hampden were cut short following the death of midfielder Liam Kelly's father from a heart attack. After paramedics worked to revive him at the final whistle, Jack Kelly was rushed to the Victoria Infirmary and died within hours.
A month later an Inverness fan collapsed and died in the Frank Beattie Stand midway through the second half of a game against Killie.
With those two incidents in mind, Shiels and Hibs manager Pat Fenlon both wanted the game abandoned.
"We need to show respect to the relevant families,'' Shiels said. "As you know we have been through that three times in just over a year. An Inverness fan lost his life and then Liam Kelly's father. Football is not as important as human life so we have shown our respect, we don't know what the outcome is but hopefully everything turns out okay.
"It seems to be pretty serious, a heart attack we were told. I heard the supporters shouting to kick the ball out and then we seen our medical team going across. The fourth official came and told me we need to stop the game. We waited a while to see if they could bring him round and continue the game but obviously it was quite serious so Pat Fenlon and I both agreed that the game should be abandoned.
"We were asked for our views on it, the officials and the match delegate [Frank Coulston] were very good. There is no decision (about replayed game), we are thinking Wednesday week, the 15th of May, that is not a definite but the most likely date.''
Coulston admitted abandoning the game was a "simple decision'' to make.
"It was very unusual,'' he said. "There is no briefing on those situations, it was something out of the blue for me. But the decision was the right one out of respect and the game had been stopped a while at that point. I was called in with the referee and chief inspector and the managers and it was a simple decision.''
Johnston added: "Obviously there was a serious health incident involving one of our supporters, a long-standing season-ticket holder. We had all the relevant medical teams on hand to issue emergency first aid. It is a suspected heart attack and the victim has been removed to hospital and we don't have any further news than that.
"Obviously our thoughts are with him and his family and we hope he will make a recovery. It is a sad occasion for everybody.''
Information from the Press Association was used in this report.