New national data show school bus-related accidents send 17,000 U.S. children to emergency rooms each year, more than double the number in previous estimates that only included crashes.

Nearly one-fourth of the accidents occur when children are boarding or leaving school buses, while crashes account for 42 percent, the new research shows.

Slips and falls on buses, getting jostled when buses stop or turn suddenly, and injuries from roughhousing are among other ways kids get hurt on school buses, the data found.

Depending on the circumstances of an accident in which a child is injured or killed while traveling to or from school, the child or the child's parents may have a cause of action against a party other than a school board, school district, school bus driver, or the like. If a child is struck by a vehicle other than a school bus--while the child is waiting at a school bus stop or crossing a street or road after getting off a school bus, for example--an action against the driver of the vehicle is a possibility.

Similarly, if a child is injured or killed in a traffic accident involving a school bus and another vehicle, it may be possible to bring an action against the driver of the other vehicle.