During the morning rush hour at the main ticket hall of London's Euston railway station, two teenage girls struggled to carry their luggage to the subway station underground.

It was their first time to London, and they couldn't find the elevator. Two passers-by stopped and offered to carry their luggage down the stairs.

The girls breathed a sigh of relief after they were told an elevator nearby would take them the rest of the way. But a sign said it was out of service due to "a mechanical defect".