Four people were injured Thursday when a school bus fell 15 off an interstate highway in San Antonio and landed in a Comfort Suites parking lot, police said. The majority of students had already been dropped off when the bus veered off the side of I-37, flipped in midair and landed right-side up, WOAI-TV, San Antonio, reported. The bus was sheared from its chassis, which ended up at a right angle to the main body of the bus. The three people aboard the bus -- the driver, a young boy and an adult monitor -- were taken to a hospital with injuries believed to be grave, including broken bones for the adults and face lacerations on the child. Another person in a separate vehicle also sustained injuries and was taken to a hospital.