BALTIMORE, SEPT. 29 -- Accidents in three races caused injury to four jockeys and the destruction of one horse today at Pimlico Race Course.

Alberto Delgado (fractured right clavicle), Jesse Davidson (dislocated right shoulder) and Clarence Ladner (bruises) -- all among Pimlico's top 10 riders -- were thrown from their mounts in separate incidents, hospitalized and released. Apprentice Eric Nied was treated for cuts and bruises at the track's first-aid station.

Ladner was the first to fall. He trailed eight horses astride long shot Dancing June in the second race, when the 4-year-old filly broke a foreleg entering the final turn. Ladner, 21, sailed over the horse's left shoulder and tumbled several times. He was removed by stretcher and taken by ambulance to Sinai Hospital.

Dancing June, a $6,500 claimer trained by Ralph Verderosa for D&R Stable, was destroyed. She won two of 30 lifetime starts.

Less than 30 minutes later, in the third race, two more jockeys were lying in the dirt following a dramatic spill in the stretch. Delgado, 23, had his mount Andy Freeze in traffic toward the rear of the 11-horse pack when the gelding appeared to clip the heels of Maurice Heron at the eighth-mile pole. Knocked off his feet, Andy Freeze unseated Delgado directly in front of Nied, astride last-place Hi Johnny Boy.

With Andy Freeze on his back, feet in the air, Hi Johnny Boy attempted to hurdle the fallen horse, throwing Nied and nearly stepping on Delgado.

"I saw it coming, but there was nothing I could do; that's what's so frustrating," Nied said. "They were pinching Albert a little bit, and I heard him holler, 'Hey, I'm in here!' I tried to shy away, but his horse tumbled right in front of me."

Neither Andy Freeze nor Hi Johnny Boy appeared injured. Smart Streak won the race, followed by 55-to-1 Rich Fleet, helping the double-triple remain unsolved a 15th straight day. Thursday's pool will begin at $155,918.20.

During the post parade before the injury-ridden third race, Davidson dismounted Maurice Heron and informed officials he would not ride the colt. Davidson was replaced by apprentice Chad Murphy, under whom Maurice Heron appeared to come in slightly, perhaps precipitating Delgado's fall.

Chief steward Clinton Pitts Jr. said stewards have requested to meet with all 11 jockeys in the race for a review of the accident. Pitts also said Davidson had the right to refuse to ride Maurice Heron without furnishing a reason. "If he doesn't want to ride, you can't make him ride," Pitts said.

Davidson said Maurice Heron appeared sore and he did not want to risk riding him.

Davidson's spill, in the fifth race, actually took place after his horse had completed the race. As she galloped past the finish line, the filly Corrie's Image took a bad step and fell, dumping Davidson, 47. Corrie's Image was unhurt, and Davidson's shoulder "popped back into place," according to a hospital report.

In the following race, another surprise materialized: Nine Wide, highest-priced in a 12-horse field at 70 to 1, won by 2 1/2 lengths and paid $148.40.

The spills came at a time when Davidson and Ladner were having productive meetings. Davidson ranks third with 35 victories, behind Kent Desormeaux and Donald Miller Jr., and Ladner has cracked the top 10 with help from agent Eric Fried.

Fried booked the jockey on five mounts today. Ladner had second call, behind Mary Wiley, on the ill-fated Dancing June, and received the mount when Wiley opted for a return ride on Universal Piece.

"We're not going to turn down anybody," Fried said of prospective clients. "The last thing you want to do is alienate people."