ARCADIA, Calif. — Santa Anita has canceled racing indefinitely to re-examine its dirt surface after the deaths of 21 horses in the last two months.

Tim Ritvo, chief operating officer of The Stronach Group, which owns Santa Anita, told The Associated Press on Tuesday that racing won’t be held this weekend, when two major races were scheduled: the San Felipe for 3-year-old Kentucky Derby hopefuls and the Santa Anita Handicap for older horses.

Ritvo wouldn’t speculate on when training and racing would resume. After this weekend, races were to be run again starting March 14 at the storied racetrack that will host the Breeders’ Cup world championships for a record 10th time this fall.

“In whole, we feel confident in the track and we’re just being very proactive,” Ritvo said. “We want to do all the testing that needs to be done. When we believe we’re in good shape, we’ll start to train over it again.”

The Daily Racing Form first reported the cancellation.

The latest fatality occurred during training on Tuesday, when a 4-year-old filly got injured and was euthanized.

“Obviously, one horse is too many,” Ritvo said. “The recent rash is just horrible. We need to definitely take a step back and evaluate everything.”

Santa Anita received 11½ inches of rain and had unusually cold temperatures in February, but it’s unclear whether track conditions played a role in any of the fatalities.

The National Weather Service was forecasting 1 to 2 inches of rain in Los Angeles County starting overnight Tuesday and into Wednesday.

“We think that (rain) could definitely contribute even though our experts are telling us not,” Ritvo said. “The tracks out here are built not for weather like that.”

Ritvo said officials are “a little bit concerned” with the latest impending storm and how the dirt surface can change from muddy to fast in a short time.

Besides re-examining the dirt track, Ritvo said all racing protocols would be looked at.