Armed police stood guard, smiling, as Liverpool's finest filed into Aintree on Ladies Day in warm sunshine, 50 years after a rainsoaked race unmatched in Grand National history.
One of the fences the field of 40 will tackle in Saturday's big race is now called Foinavon, after the 1967 winner, who profited from Aintree's biggest pile-up.
Approaching the 23rd of 30 fences, the joint lowest on the course at 4ft 6ins, a loose horse, ironically named Popham Down, suddenly veered across in front of the field.
Horse after horse had nowhere to go.
Jockeys fell left, right, and in the case of Stan Mellor on board The Fossa, into the fence.
"Falls happen a couple of times a week," the three-times champion jockey told me, but this was different.
"Sitting in the fence, it was a bit cosy. Twenty or 30 horses coming towards you - you don't hang about.
"I ran to the outside, which was the safest bet. Fear didn't come into it," added Mellor, who turns 80 on Monday.
"Common sense did - I was off the fence like a shot."
Foinavon, a completely unfancied 100-1 shot, was far enough behind for jockey John Buckingham to skirt round all the trouble and march on to victory, as chaos reigned behind.
Could it happen today?
World Horse Welfare chief executive Roly Owers said: "Never say never, but the chances are much less likely."
He pointed to the field now being smaller than 50 years ago, and safer fences meaning fewer fallers and therefore fewer loose horses.
"But probably most significantly, over the last few years, Aintree have invested a lot in runout channels for loose horses, where they are collected up before they can disrupt the rest of the race," he added.
Buckingham, who became a jockey's valet, died last December, thus missing the anniversary of his part in the Grand National's most unlikely triumph.
But Stan Mellor, one of those left searching for his horse at the 23rd fence, is at the race as a guest of the Aintree chairman.