Germanwings spokesman Heinz Joachim Schoettes said the passengers from the Cologne Airport flight to Zurich were taken off their original plane Monday due to mechanical issues and moved to a series of buses meant to take them to their replacement plane, TheLocal.de reported Wednesday.
However, one of the buses, carrying 12 passengers, did not receive instructions about where to go until the plane had already departed. The left-behind passengers said all of their luggage was on the plane that left for Switzerland.
Schoettes said the last bus in the group was supposed to carry a "boarding completed" sign so the plane would know when to depart, but the sign was apparently displayed by the wrong bus.
"We can only apologize to everyone," the spokesman said. "It was a series of unfortunate events."
The passengers were issued refunds for their tickets and given seats on a flight departing for Zurich the following day.