DEL MAR, Calif. - Tuscan Evening, the winner of six stakes for turf females this year and a leading contender for the Eclipse Award as outstanding turf female, died of an apparent internal injury after a workout at Del Mar on Sunday, according to a racing official.\r\nTuscan Evening collapsed while galloping out after a six-furlong workout on turf in 1:15.60. She was being prepared for an expected start in the $750,000 Beverly D Stakes at Arlington Park on Aug. 21.\r\nOwned by Will de Burgh and trained by Jerry Hollendorfer, Tuscan Evening, 5, won 12 of 27 starts, including nine stakes, and earned $1,138,508.\r\nThe exact cause of death was not immediately known. According to California Horse Racing Board medical director Dr. Rick Arthur, a necropsy will be conducted on Tuscan Evening at a laboratory in San Bernardino, Calif., affiliated with UC-Davis. Tuscan Evening was scheduled to be sent to the lab on Sunday morning.\r\n&quot;More often than not, we found out a specific cause,&quot; Arthur said.\r\nAn Irish-bred, Tuscan Evening began her career in England and Ireland, where she placed in five stakes, including a second in the Group 1 Irish 1000 Guineas. After she was transferred to Hollendorfer in California in late 2008, she won 12 of her next 16 starts and $1,055,655.\r\nThis year, Tuscan Evening was unbeaten in six starts, highlighted by four stakes wins at Santa Anita and a win in the Grade 1 Gamely Stakes at Hollywood Park in May. In her most recent start, she won the Grade 3 Modesty Handicap at Arlington Park on July 17.