The gruelling Grand National came under renewed fire after the "unacceptable" death of two horses at the notorious Becher's Brook fence prompted passionate calls for a radical safety review.
Cheltenham Gold Cup winner Synchronised and According to Pete were both put down after falling at Becher's Brook, taking the total of fatalities at this year's three-day Aintree meeting to three.
Two horses also died in the 2011 Grand National, leading officials at the course to modify the daunting Becher's challenge.
"The death of two horses at the Grand National, bringing the total to three at the Aintree meeting, is totally unacceptable," Gavin Grant, the chief executive of the Royal Society for the Prevention of Cruelty to Animals (RSPCA) told the BBC.
"In its current format, the risks to horses are not appropriate and we want an urgent examination of the Grand National, including a number of fences such as Becher's Brook, where horses are continuing to die despite safety improvements."
Other animal welfare campaigners blasted Saturday's race as "the worst kind of mob entertainment".
"The Grand National is a disgusting and shameful spectacle masquerading as sport," said Andrew Tyler, the director of Animal Aid.
"For anyone who genuinely cares about horses watching this race was an utterly depressing and melancholy experience."
Synchronised had already shown signs of distress before the race started when the nine-year-old unseated veteran jockey Tony McCoy.
The horse broke away and it was several minutes before animal and jockey were reunited, delaying the start of the race by 10 minutes.
In a damage-limitation exercise, Aintree owners, as well as the British Horseracing Authority (BHA), moved to confront the gathering storm.
Tim Morris, the director of equine science and welfare for the BHA, said: "In both cases the horse incurred a fracture to the leg and the humane option was to put the injured horses down."
He added: "We will examine closely the circumstances which led to both incidents. The key data from these accidents will be collated, as is the BHA's policy in the event of any serious equine injury.
"Each year the BHA and Aintree review all incidents which occur during the Grand National meeting and consider what measures can be taken to address the risk of a repeat in the future."
David Muir, an equine consultant to the RSPCA, told The Guardian that drop fences -- those like Becher's on one side of which the ground is lower than on the other side -- should be removed before next year's race.
"I think the Grand National has a future if it changes and makes the risk factors lower and more acceptable," Muir said.
"If racing is to continue, racing must realise that people are concerned about horse fatalities on racecourses and the impetus to reduce the risk factor has to be greater."
For Synchronised's trainer, Jonjo O'Neill, the drama brought back the awful memory of when he rode Gold Cup winner Alverton in the 1979 National.
That horse also came to grief at Becher's and was also put down.