The close-knit racing community was thrown into grief after jockey Simone Montgomerie, a 26-year-old mother of two, had been killed in a racing accident at Monday's Darwin Cup Carnival.

The Telegraph reported that Montgomerie fell from her horse Riahgrand and was trampled by trailing horses in front of a shocked audience of 25,000. Both horse and rider were in the lead 100 meters from the finish line when the accident occurred.

"No other horse seemed to be involved. There was no stumble," one eyewitness told The Telegraph.

ABC reported that the jockey was immediately transported to Royal Darwin Hospital, where she died soon after arrival.

"The Darwin Turf Club, along with the entire industry, offer our deepest condolences and sympathies to the family of Ms Montgomerie," Darwin Turf Club chairman Brett Dixon said in a statement.

Dixon added that the remaining races will be cancelled to make way for a full-blown investigation into the incident, which has sent shock waves throughout the racing world.

Even while Montgomery was being treated at the hospital, safety concerns were already being raised by the jockeys present at the race. "We've spoken to the riders and some of them are quite concerned and quite upset," Darwin Turf Club chief steward Lindsay Lane told The Guardian.

Ironically, the accident occurred only two days after the National Jockeys' Celebration Day, which publicizes the support given to families of those killed or injuried while working with horses.

Montgomerie was part of a prominent jockey family. She started her racing career in South Australia before moving to Darwin in 2009 as an apprentice to trainer Michael Hickmott. Her father, Peter Montgomerie, trained 2005 Melbourne Cup runner-up On A Jeune. Her mother also owned the winning horse in Monday's tragic race.