Three people were injured on April 12, 2007 at about 2:00 p.m. after a collision on Interstate 270 closed down all southbound lanes near Montrose Road in Rockville. Montgomery County Fire and Rescue spokesman Pete Piringer said a school bus was involved in the collision, along with three other cars. No children were on board at the time. Piringer said the injuries do not appear to be life-threatening. Maryland State Police are investigating the cause of the collision.