From
http://www.pedigreequery.com/six+drivers
"January 4, 2014: Died of a neck fracture after breaking loose and colliding with another horse, Caixa Eletronica, during training hours at Belmont. Both horses were killed instantly."
If the 'killed instantly' is accurate which I have no reason to believe it's not then at least neither horse suffered. So sad. RIP to both of these horses.
-Five