Should School Buses Have Seat Belts?

The vast majority of school buses in our country are not equipped with seat belts.  A lawsuit in Indiana over a fatal school bus accident is accusing a school bus manufacturer of producing an unsafe bus due to the lack of seatbelts.  https://www.indystar.com/article/20120319/NEWS02/203190344/Lawsuit-in-fatal-school-bus-crash-focuses-on-seat-belts?odyssey=tab|mostpopular|text|NEWS