SANTA ROSA, Calif. — Organizers of a motorcycle event in California offered condolences Tuesday to the families of two rising young riders who died from crashes in two separate races over the weekend.

AMA Pro Racing issued a statement saying it was “deeply saddened by the tragic loss” of 17-year-old Kyle McGrane and 20-year-old Charlotte Kainz, whose fatal crashes occurred Sunday during an event at the Sonoma County Fairgrounds.

“Today we are all mourning,” Michael Lock, the CEO of AMA Pro Racing, said in the statement. “Charlotte and Kyle were talented competitors with bright futures. Our deepest condolences go out to their families and friends in this time of need.”

Both riders were in AMA’s junior division, according to The Santa Rosa Press Democrat, and were participating in races at the Ramspur Winery Santa Rosa Mile AMA Pro Flat Track Motorcycle Race.

McGrane of Gap, Pennsylvania, died Monday of injuries sustained when he crashed coming out of the fourth turn of the final lap of his race, Lock told The Santa Rosa Press Democrat.

McGrane had been participating in AMA Pro racing since 2015 and had “a growing fan base nationwide,” the statement said.

In a race earlier Sunday, Kainz of the Milwaukee, Wisconsin, area, collided with another rider and was rushed to a hospital where she later died.

Kainz was a “beloved rider” who “brought smiles to the faces of everyone she met,” the statement from AMA Pro Racing said. It said she had earned her professional license in Pro Flat Track in 2015.

Lock says it is rare that anyone dies at a race, let alone two people.

“I don’t know of this happening in the living memory of our sport,” he told The Santa Rosa Press Democrat. “We are all in complete shock.”

Officials are reviewing communication procedures to see whether any aspect of the response could have been improved.

Information from: The Santa Rosa Press Democrat,