The first announcements were made around 04:00, when officials started asking people to stop going to the Sangam nose and instead take a dip at the nearest river bank they could find.

Once form I-129 has been accepted by USCIS, the visa applicant must present himself or herself at the nearest U.S. consulate or embassy outside the U.S. for an interview.

"It was only a short walk from any German city to the nearest concentration camp," says the American voice-over.

He did not hesitate, grabbing and stabbing the girl nearest to the door as soon as he walked in.

In a properly installed system, people are then directed by announcement to the nearest fire exits, with flashing lights for people who are hearing-impaired or audible warnings for those sleeping.