McEvoy's win was also special for the family as it was Cathy's first time seeing him win the Melbourne Cup after missing his 2016 ride with Almandin.
There was a point there I thought we might have won the Melbourne Cup.
Ryan Moore and The Cliffsofmoher (L) drop back.
"This was an unfortunate incident that happens infrequently, with Victoria having one of the best safety records in world racing", a Racing Victoria statement read.
The Cliffsofmoher was an Irish horse ridden by English jockey Ryan Moore.
A Kiwi punter has won nearly $100,000 after splurging out on the Melbourne Cup victor Cross Counter, but has been eclipsed by an Australian who has won A$500,000.
Channel 7 commentator Bruce McAvaney said it was a "tragedy" while his colleague Richard Freedman had made a point of mentioning how agitated The Cliffsofmoher looked before the race.
Aidan O'Brien's head lad TJ Comerford was seen speaking to stewards more than an hour before the Cup, but a Racing Victoria spokesperson said it was only for clarification over what riding tactics the stable might use in the race.
The Flemington track was lashed with up to 50mm of rain on the morning of the Melbourne Cup, but was the subject of two track upgrades later in the day as the sun broke through intermittently.
For jockey Kerrin McEvoy, it is his third Melbourne Cup, and he becomes the first jockey to complete the Everest-Cup double.
Fan favourite Red Cadeaux, who finished second on three occasions, was pulled up in the final straight of the 2015 edition of the race and it was later confirmed he suffered a break in his left foreleg. The horse was euthanised after the race at Flemington.
Admire Rakti and Araldo were both killed in the 2014 Melbourne Cup.
"The Melbourne Cup is much more than just a horse race, it's a 158 year old social and cultural tradition that brings Australia and New Zealand to a standstill", says Racing Board chief executive John Allen.
The horse clipped the heels of another runner and injured a foreleg when falling as the field turned for home.
Five other jockeys, including winning jockey Kerrin McEvoy, were also sanctioned for breaching the whip rule. As the remaining 23 horses passed the post, The Cliffsofmoher received medical attention before vets determined it was "unable to be saved".