Two IndyCar drivers were released from a Las Vegas hospital after being treated for injuries suffered in a horrific crash that claimed the life of two-time Indianapolis 500 winner Dan Wheldon, officials said on Monday.American JR Hildebrand and Briton Pippa Mann both spent a night at the University Medical Center after suffering injuries in a 15-car pileup during the opening laps of Sunday\'s IndyCar season-finale.Mann, who had surgery to clean and assess a severe burn to the little finger of her right hand, will need a subsequent surgery in two-to-three weeks to fully repair the injury but is expected to make a full recovery, IndyCar in a statement.Hildebrand suffered a severely bruised sternum and was held overnight for observation.