2001 Cadillac SLS 20 below

My son tried to start my car in 20 degree below 0 weather with little anti freeze and rest water while it had been sitting for 6 hrs. He saw white smoke from exhaust and noises from heater. I mere put the key in ignition and turn key and all sorts of noises started with the regular ignition ding. What did he break. I was guessing the pulley on water pump but it seems