Contact people in the car. Make sure no one has accidentally activated the emergency STOP switch. If not, assure them that help is being called.
Call your elevator service company and advise them that you have an entrapment. Continue communicating with people in the car.
Assure them that they are in no danger, and remind them that they should remain in the cabin until help arrives. Advise them of the technician’s estimated arrival time.
DO NOT attempt to open elevator doors or any car-top doors. Wait for help to arrive. You can put yourself or passengers in severe peril if you try to remove passengers yourself.