A Houston-area man is in custody after allegedly hijacking an ambulance at gunpoint with a patient in the back. KPRC television reports the incident happened around 3 am this morning on the South Loop in Houston. Firefighters said their ambulance was taking a patient to the hospital when a car stopped in front. Then a man with a gun forced the driver to get out, took over the ambulance and drove off with a patient and an EMT in the rear. The gunman also reportedly fired off some rounds, but not towards anyone. The EMTs called for help, and dispatchers were able to track the ambulance until police caught up with it.