One of the horses was sired by Triple Crown winner American Pharoah and another by Belmont Stakes winner Tonalist.
Ten racehorses on their way from Florida to New York were killed early Sunday morning when the articulated truck in which they were riding hit a specific average on the New Jersey Turnpike and went up in flames, authorities said.
The two truck drivers were taken to hospital, according to horse trainer Christophe Clement, who led Tonalist to victory on the Belmont Stakes in 2014.
“We are all devastated by the news and heartbroken – we are working to understand what happened,” Clement wrote on Twitter.
The accident occurred around 3 a.m. on the northbound lanes of the Turnpike outside Trenton, New Jersey, in East Windsor. Trooper Charles Marchan, a spokesman for the New Jersey State Police, wrote in an e-mail on Sunday.
The cause is still under investigation.
Mr. Clement wrote that the trailer had been operated by Sallee Horse Vans. The company did not immediately respond to a phone message asking for comments, but its owner, Nicole Pieratt, told the racing news website BloodHorse that the drivers had been treated for smoke inhalation and released from hospital.
At least two of the deceased horses had champion bloodlines and had recently ridden in Florida. They belonged to West Point Thoroughbreds based in Saratoga Springs, New York, and confirmed their death.
One of the horses was Under the Oaks, a 3-year-old filly by American Pharoah, who in 2015 became the first horse to win the Triple Crown since Affirmed performed the feat in 1978. On May 30, Under the Oaks finished sixth at her debut at Gulfstream Park in Florida.
Another one who died was Hot Mist, a 3-year-old filly by Tonalist, the horse that California Chrome refused to give the Triple Crown in 2014 by winning the Belmont Stakes. On May 16th she won her first race at Tampa Bay Downs.
“Just rest easy, Hot Mist & Under the Oaks,” West Point Thoroughbreds wrote on Twitter.
The other dead horses were not identified.
The accident occurred less than five kilometers from where a Walmart tractor-trailer crashed into the back of a luxury car on June 7, 2014 with a group that included comedian Tracy Morgan.
Mr Morgan suffered serious injuries in the crash, which killed James McNair, a comedian named Jimmy Mack. The truck driver had been awake for 28 hours before the accident and was driving 20 miles per hour over the 45 m.p.h. speed limit in a work zone by the turnpike, the National Transportation Safety Board found.