Four people, including a two-year-old, were injured in a cross-over collision on I-70 near the 201 mile marker Friday morning.According to the Missouri State Highway Patrol, Justin Green, 28, Wentzville, was traveling eastbound on the interstate when he lost control of his 2004 Cadillac and crossed the median into the westbound lane striking another vehicle head-on.Green's car continued to slide striking two more vehicles. A fourth vehicle was hit by debris.The accident occurred about 8 a.m.Mary M. Allison, 68, Chesterfield,  a passenger in the first vehicle hit, was seriously injured in the accident. She was taken by an ARCH helicopter to Mercy Hospital St. Louis.Brycen Green, 2, Wentzville, a passenger in Green's car, was moderately injured and taken to Mercy Hospital St. Louis by ambulance. Police said he was in a car seat at the time of the collision.Green, who was the only one involved in the crash who was not wearing a safety device, suffered minor injuries. He was also taken to Mercy Hospital St. Louis.Patricia Benne, 63, Ballwin, who was in the third car struck by Green's car, also had minor injuries. She was taken to St. Joseph's West Hospital by ambulance.The interstate was shut down for nearly an hour after the accident.Witnesses at the scene told The Record Green's car went over the top of the median cable.Earlier story:A multi-vehicle  accident on  I-70 near the 201 mile marker that occurred shortly after 8 a.m. Friday tied up both the Eastbound and Westbound lanes of the Interstate, as well as the North service road, for nearly an hour.At least 5 vehicles were involved in the crash.Emergency personnel treated a number of injured people, including at least one child.Some of the injured were transported from the scene by helicopter.Witnesses  told The Record that a white Cadillac, traveling Eastbound on I-70 crossed the medium and drove into the Westbound lanes of the Interstate striking several cars. The Cadillac was forced onto the North service road by the collision.Man Reportedly Ejected From Vehicle in Mult-Vehicle Accident