Among the victims of the Germanwings A320 crash in France were 15 German schoolchildren who were returning from an exchange program, according to The Local German newspaper. The students had been on a trip with Catalonia’s Giola Institute secondary school in Llinars del Vallès, media reported.

“This is terrible news that has reached us from France,” German Vice Chancellor Sigmar Gabriel wrote on his Facebook page, according to the Guardian. “We are all stunned by this terrible catastrophe that has taken so many people. Our thoughts are with the victims and their relatives…. Personally, and on behalf of German social democracy, I express my deep sorrow.”

While the identities of the plane’s 150 passengers and crew have not yet been released, French President François Hollande said they were mostly of German, Spanish and possibly Turkish origin. He said it was uncertain whether any French nationals were onboard.

Families of the passengers began gathering at Düsseldorf Airport in Germany, the plane’s destination, with plans to greet people arriving on the Germanwings flight. They were comforted by police and airport personnel upon arrival. Grief counselors were on hand to assist. Families also gathered at the airport in Barcelona.

“Lufthansa and Germanwings have established a telephone hotline,” Germanwings said in a statement. “The toll-free 00800 11 33 55 77 number is available to all the families of the passengers involved for care and assistance.”

A Germanwings A320 aircraft crashed in the French Alps on Tuesday, presumably killing all who were onboard. The plane was en route from Barcelona to Düsseldorf.