NASCAR fans at Daytona injured when large chunks of debris from car fly into grandstands

Kyle Larson (32) goes airborne and into the catch fence during a multi-car crash involving Justin Allgaier (31), Brian Scott (2) and others during the final lap of the NASCAR Nationwide Series auto race at Daytona International Speedway, Saturday, Feb. 23, 2013, in Daytona Beach, Fla. Larson's crash sent car parts and other debris flying into the stands injuring spectators. (AP Photo/John Raoux) (The Associated Press)

Emergency officials put out a fire from driver Kyle Larson's engine after his car hit the wall and safety fence along the front grandstands on the final lap of a NASCAR Nationwide Series auto race at Daytona International Speedway in Daytona Beach, Fla., Saturday, Feb. 23, 2013. Larson's crash sent car parts and other debris flying into the stands injuring spectators. (AP Photo/Phelan M. Ebenhack) (The Associated Press)

With the start of the Daytona 500 just hours away, NASCAR officials still have some cleaning up to do amid growing questions about fan safety.

The season opener will go off as planned Sunday less than 24 hours after at least 33 people were injured when a car flew into the fence during a NASCAR race at Daytona International Speedway, sending a tire and large pieces of debris sailing into the stands.

The final-lap accident Saturday marred the second-tier Nationwide Series race on the eve of a spectacle often called the Super Bowl of motorsports. Late into the night, track workers were scrambling to repair a huge section of fence that separates fans from the high-speed track.

Speedway President Joie Chitwood III has a news conference scheduled for Sunday morning to give the latest update on repairs and any safety changes that could be made before the "Great American Race."