Ontario Provincial Police are sharing new details about a crash that closed the eastbound lanes of Highway 401 for nearly five hours on Wednesday. The crash happened around 2 p.m. just east of Highway 8. Police said at least six vehicles were involved in the collision, including a dump truck which had spilled its load of sand and gravel. One person was seriously hurt but was later said to be in stable condition. According to OPP, evidence gathered at the scene showed speed and careless driving were factors in the crash. They specifically called out the driver of a sedan. Police said charges are pending. The eastbound lanes remained closed for the remainder of the afternoon so crews could clean up the mess left on the highway.