They do need to closely look at what to do to protect the spectators. Larry McReynolds has come out recommending that rows be removed to add greater distance. I would be curious to know where the injured spectators were seated. We're they front row or fifteen rowa up equal to the top of the catch fence.
This is actually something Daytona is addressing with Daytona Rising. Their fence heightening has been widely publicized, but they've also moved the grandstands back away from the track and upwards. Most of the stands and rows where fans were injured by Larson's car in 2013 will ultimately be removed. They've also banned fans from standing in the area up next to the fence while the race is going on.