A special needs school bus w/ wheelchair occupants on board was involved in a MVA with a minivan at the Intersection of Route 304 and West Washington Avenue. Initial response was from Nanuet Ambulance mutual aid. A total of four parties were transported to local area hospitals with minor injuries. Special needs children were extracted through the emergency door in wheelchairs as the HC Ramp was inoperable. Responding units included Nanuet & Pearl River Ambulances, Paramedic Unit21, Orangetown PD and Bus Company representatives. Traffic was snarled at the intersection for approximately 45 minutes due to vehicle extraction and police investigation and tow truck retrieval.