Two CMS school buses collided at Nathaniel Alexander Elementary School in the University Area this afternoon, sending 20 people to the hospital with minor injuries. Police say the bus driver who rear-ended another bus coming out of the school parking lot was supposed to be wearing glasses or contacts, but wasn't. Her license requires her to use corrective lenses. Police say the driver was also cited for failing to slow down. A CMS spokeswoman says 49 students were aboard buses 305 and 1415. Eighteen of the students and both drivers were transported to the hospital.