ELMONT, N.Y. – Caixa Eletronica, a popular graded stakes winner, and Six Drivers, a maiden, suffered fatal injuries when the two horses collided head-on during training hours Saturday morning at Belmont Park. Six Drivers had unseated his rider, Julio Pezua, near the starting gate on the training track, and went running loose the opposite, or wrong way, when he barreled into Caixa Eletronica, who was galloping near the five-furlong marker. Carlos Castro, the exercise rider on Caixa Eletronica, was taken to North Shore University Hospital where he was diagnosed with a fractured pelvis and will require reconstructive surgery on his face, according to Byron Hughes, the assistant to Todd Pletcher, trainer of Caixa Eletronica. Pezua, who said his horse spooked from the starting gate which caused him to rear up, was uninjured. According to New York Racing Association officials, both horses died instantly. Caixa Eletronica suffered a fractured skull, while Six Drivers, a recent $16,000 claim by trainer Chris Englehart, suffered a fractured neck, according to NYRA. Mike Repole, who owned Caixa Eletronica since claiming him for $62,500 in March 2011, said he was in shock when told the news this morning by Pletcher, who was at Palm Meadows in south Florida. Pletcher was informed of the incident by Hughes. “[Pletcher] was as devastated telling me as I was hearing the news,” Repole said. “I’m in shock. For such an iron horse to unfortunately pass away this way really makes no sense.” Caixa Eletronica, a 9-year-old son of Arromanches, had a record of 23 wins, 9 seconds, and 11 thirds from 69 starts and earned $1,863,505. Since being claimed by Pletcher and Repole nearly three years ago, Caixa Eletronica won 11 races from 29 starts and earned $1,601,800. In 2012, he won the Grade 2, $1 million Charles Town Classic and the Grade 2 True North, a race in which he made up seven lengths in the last eighth of a mile. His other stakes wins included the Grade 3 Westchester in 2011 and the Grade 3 Fall Highweight in 2012. In his last two starts, Caixa Eletronica won the Duck Dance Stakes at Belmont in October before finishing fourth in the Fall Highweight at Aqueduct on Thanksgiving. Caixa Eletronica, who was scratched out of a starter allowance on New Year’s Day because of ineligibility, was pointing to the $100,000 Evening Attire here on Jan. 25, Repole said. Pletcher, in an interview at Gulfstream after he won the Old Hat Stakes with Sweet Whiskey, called the loss of Caixa Eletronica “heartbreaking.” “He’s a barn favorite,” Pletcher said. “Like I’ve said time and time again, to me he was everything that was good about the game. You take a horse from a modest beginning and literally get to the pinnacle of racing. He showed up every time.” Repole said he had considered retiring Caixa Eletronica at the end of both his 7- and 8-year-old seasons, but the horse was sound and seemed to enjoy running and training so much that he kept him going. Repole said he turned down offers from farms in Indiana, Oklahoma, and overseas to stand the horse as a stallion. Repole said his plan was to retire the horse to Old Friends in Saratoga. “Growing up in Queens these are the horses that I fell in love with, not the Saturday horses, but the Wednesday and Thursday horses,” Repole said. “Caixa was that type of horse that turned into a special horse.” ** Following Sunday’s card, Aqueduct will be dark for three straight days before starting a Thursday-through-Monday schedule.