This year's Dublin marathon was cancelled on Tuesday, despite Ireland's move to lift coronavirus lockdown measures, indicating potential long-term disruption caused by the outbreak.
The race had been due to take place on 25 October. By that date, Ireland plans to have fully lifted restrictions in a staggered process that began on Monday.
But organisers indicated the race - which last year had 22 500 entrants - would still not go ahead because of safety fears.
"We made the difficult decision in the best interest of the health and well-being of all those involved in making our events such a success from runners, supporters, volunteers, sponsors, to suppliers," said race director Jim Aughney.
"We explored many alternatives for running the events safely but ultimately none were viable," he said in a statement.
Ireland's "roadmap" to reopen the nation has scheduled the last of five stages to lift coronavirus lockdown measures for August.
A government ban on mass gatherings of more than 5 000 people is also set to expire at the end of that month.
The decision to ban the marathon indicates the fallout of coronavirus may last longer than suggested by official plans and could hit other scheduled - or rescheduled - events.
The London Marathon, for example, has been postponed to 4 October. Last year, just under 43 000 runners started the race, with tens of thousands of spectators lining the route.
Ireland has suffered 1 547 deaths from Covid-19, according to the department of health.
On Monday the number of daily deaths had fallen from a peak of 77 to just four.
"We have suppressed the virus and limited its impact on public health," said chief medical officer Tony Holohan on Monday.
"We need to sustain this in the weeks and phases ahead."