Abstract: Method and arrangement for obtaining and conveying information about occupancy of a passenger compartment of a vehicle including at least one wave-receiving sensor for receiving waves from the passenger compartment. Information about the occupancy of the passenger compartment is generated based on the waves received by the wave-receiving sensor(s) and transmitted, e.g., through a cellular phone system, to emergency response personnel to enable them to respond accordingly. The information about the occupancy of the passenger compartment may be generated by a processor applying pattern recognition techniques so that any occupants of the seat may be classified and such classification transmitted to the emergency response personnel. The wave received by the wave-receiving sensor(s) may also be used to determine the number of occupants in the vehicle and/or whether the occupants are moving after a crash.