SHREVEPORT, La. (AP) — Officials preparing for the annual State Fair of Louisianain Shreveport have made changes to prevent amusement ride accidents like the one that injured a 4-year-old last year.

At the 2011 State Fair, Sheldon Lewis was critically injured when another child activated a ride. The Times of Shreveport reports that Lewis was trapped in a space between the ride and the floor for more than 20 minutes.

Among this year's changes is a later weekday opening time of 3 p.m. for rides. Rides won't be operating when schools and other groups take field trips with a limited number of adults to supervise large groups of children. The later start also gives ride operators more time to rest so they're more alert when the rides are open.