A polar bear operated on by the surgeon for classic winner Barbaro died just hours after surgery Monday.

Dean Richardson, DVM, Dipl. ACVS, operated on Alcor, a 750-pound bear with two badly broken bones just above its right paw, at the University of Pennsylvania’s New Bolton Center on Monday afternoon and stabilized the wrist during surgery with locking plates.

The bear was in a refrigerated truck on the way to recover at the Cleveland Zoo, which has facilities favorable for allowing injured bears to heal. Alcor had been stable and was waking from anesthesia when it died, the University of Pennsylvania’s George D. Widener Hospital said in a statement Monday night.
Alcor will be returned to the hospital to undergo a post-mortem, the New Bolton Center said.

Zoo officials do not know how Alcor broke the leg, but they suspect it happened Aug. 11 while the bear was playing with its brother Mizar, another 7-year-old bear who has been at the zoo since 2001. A vet at the Cleveland Zoo put Erie Zoo officials in touch with Richardson’s medical team