DAYTONA BEACH, Fla. — As emergency workers tended to injured fans and ambulance sirens wailed in the background, a somber Tony Stewart skipped the traditional post-race victory celebration following the NASCAR Nationwide Series race Saturday at Daytona International Speedway.A last-lap accident sent rookie Kyle Larson’s car sailing into the fence that separates the track from the seats, and large chunks of Larson’s car landed in the grandstands. The car itself had its entire front end sheared off, with a piece of burning engine wedged through a gaping hole in the fence.Neither NASCAR nor Daytona International Speedway officials had any immediate comment on potential injuries.“There obviously was some intrusion into the fence and fortunately with the way the event’s equipped up, there were plenty of emergency workers ready to go and they all jumped in on it pretty quickly,” said NASCAR President Mike Helton. “Right now, it’s just a function of determining what all damage is done. They’re moving folks, as we’ve seen, to care centers and take some folks over to Halifax Medical.”Stewart, who won for the 19th time at Daytona and seventh time in the last nine season-opening Nationwide races, was in no mood to celebrate.“The important thing is what going on on the frontstretch right now,” said Stewart, the three-time NASCAR champion. “We’ve always known, and since racing started, this is a dangerous sport. But it’s hard. We assume that risk, but it’s hard when the fans get caught up in it.