A close friend of jump jockey JT McNamara said he was sick to the stomach as he watched the devastating fall which left the 37-year-old paralysed.
McNamara, a Limerick jockey who had planned to retire from the sport this summer, has been told he is paralysed from the neck down following a fall at the Cheltenham Festival.
Barry Potts, a horse trainer from Clady, near Strabane, was best man at McNamara's wedding.
The Tyrone man said he hopes the father-of-three's renowned determination will now carry him through.
McNamara remains in hospital after fracturing two vertebrae in the fall last month.
"You knew when the horse hit the ground and he hit the ground, it was such a slap," Mr Potts said.
"I knew when he did not move there was something wrong because he would usually bounce up again. That was always the way."
The racing enthusiasts, who met at point-to-point races, have known each other for 20 years. They worked together eight years ago for Limerick horse trainer Enda Bolger.
"As far as I know he was thinking of retiring after (the April meeting at) Punchestown.
"I knew it was not good, but I didn't know the extent of it," he added.
"I had been following it on the internet and speaking to Enda Bolger. But I heard at the weekend that he was paralysed.
"It would make you sick to your stomach. Even talking about it now would make you sick to your stomach. Everybody feels a bit sick about it. They're shocked. It's something you do not expect."
The equine community is hopeful, however, that McNamara will make a recovery following the dreadful fall.
"There's another young lad, (jockey) John Joe Bright, who got a fall. He got the same thing, third and fourth vertebrae... they told him he would be paralysed. But he can lift the shoulders and arm a bit," Mr Potts added.
"Hopefully that's just the worst case scenario that they've given JT. Fingers crossed he'll get something moving."
Leading jockey Ruby Walsh has already said he is in "no way downbeat" about JT McNamara's future.
"We have all read the reports about his diagnosis of paralysis, but it is far too early to be drawing any firm conclusions."
JT McNamara was injured in a fall in the Fulke Walwyn Kim Muir Challenge Cup in last month's Cheltenham Festival. The 37-year-old amateur, who was airlifted to Bristol, was reported to be in a "very positive" frame of mind despite suffering a serious neck injury which has resulted in paralysis. In a statement the McNamara family said: "He is greatly appreciative of the many messages, cards and letters received and also wishes to thank the Frenchay Hospital."