During their exile the Jewish people “sat and wept” by the streams of Babylon when they remembered Zion. Parents in Belgium wept at the news that a tour bus carrying schoolchildren home from a class ski trip slammed head-on into a tunnel wall in the Swiss Alps, killing 22 Belgian students and six adults late Tuesday night.

As authorities tried to piece together what happened, parents, classmates, and rescue workers struggled to grasp the awful turn of events. Only days earlier the children had updated a lively blog about the highlights of their adventure: ravioli and meatball dinners, cable-car rides, and sing-a-longs.

Police said the bus was not speeding and everyone aboard had been wearing seat belts when it crashed inside the 1.5-mile Tunnel de Geronde on a highway near the southern Swiss tourist town of Sierre. No other vehicles were involved. Belgian authorities flew anxious parents and relatives to the site and called for a day of mourning.

Investigators were still trying to determine how a modern bus, a rested driver, and a seemingly safe tunnel could produce one of the deadliest highway crashes in Swiss history. Dr. Jean-Pierre Deslarzes, medical director of the local Swiss rescue service OCVS, said first-responders were traumatized because so many of the victims were children around 12 years old.

The accident virtually shredded the front end of the bus, leaving only small, barely recognizable pieces in place. Passengers were trapped inside. “We found an apocalyptic situation when we arrived,” said police commander Christian Varone.

Sources: An article by Frank Jordans, Raf Casert, and Robert Wielaard for the Associated Press