An ambulance is a vehicle for transporting sick or injured people to, from, or between places of treatment for an illness or injury.
Morlocks Ape and Annalee stole an ambulance so they could get medical supplies for Leech, who was incredibly sick. It crashed into Rockefeller Center where they met up with Storm, Jubilee, and Logan. They grabbed as much supplies as they could and went off to help Leech.