Aintree and the British Horseracing Authority will review the deaths of three horses during the three-day Grand National meeting.
Up for Review suffered a fatal injury in the National on Saturday after it was brought down at the first fence.
It is the first death since 2012 in the race, which was won by Tiger Roll for the second successive year.
Forest Des Aigles and Crucial Role both died on day two of the meeting on Friday at the Liverpool racecourse.
Track authorities and the BHA review the fixture every year and the three deaths will be scrutinised.
"As a sport of animal lovers, we wanted every horse to come home - and sadly that's not been the case with Up For Review," said Jockey Club Racecourses North West regional director Dickon White.
"All of us at Aintree extend our sympathies to owners Andrea and Graham Wylie and the team behind the horse.
"You have to go back to 2012 since we lost a horse in the Grand National, thanks in part to the huge amount of effort and investment we put into horse welfare.
"However, while you cannot remove all risk from our sport, we will analyse what happened and leave no stone unturned in doing so."
The RSPCA said it was "deeply saddened and concerned to see the deaths of three horses at Aintree this year".
It added: "The death of any horse is always one too many and it's crucial that steps are urgently taken to reduce the risk of these tragedies."