Many of the 16 children from Joseph Koenig School killed in the Alps had texted their friends shortly before take-off to tell them how much they were looking forward to being home again.
Among them was Elena Bless (16), who after enjoying the nine-day exchange in a village outside Barcelona, was excited about seeing her friends and family.
But just half-an-hour into the flight home the plane went down, killing 14 girls, two boys and two teachers from the school in Haltern am See.
Elena's best friend, Philippa (15), said: "I just can't believe it. I still think they are going to come back and tell us all about their adventures and what a great time they had. But they are not coming back.
"Elena wanted to go to university after school. She also wanted to travel the world. She'd already been to many places because her parents travel a lot."
The two girls had exchanged text messages during the time they were apart, with Elena also sending Philippa photographs of the sites they had visited around Catalonia during the trip.
Yesterday, counsellors were on hand to offer support, and each class took it in turn to pay silent tribute to their friends at an impromptu shrine of candles and flowers. At an emotional press conference held at the town hall, Mayor Bodo Klimpel said: "For many families in Haltern am See the world has stopped turning today.
"We stand speechless before a tragedy in which 18 young people - 16 school girls and boys from the 10th grade and their teachers - have not come back from their exchange programme in Spain."
At the Spanish school which hosted the exchange students, there were similar scenes of grief.
Pupils of the Giola secondary school in Llinars del Vallès, 24km outside Barcelona, remembered their German friends.
Raúl has not yet reached the age for one of the language exchanges the school has been organising with Haltern for 15 years, but his cousin had hosted a German girl who was among the dead. "She was shy but she absolutely loved her time here," Raúl recalled. "Imagine, she had never been to a beach before."
Locals gathered in front of Llinars' town hall at midday to pay silent tribute to the dead.
At the school, teachers spoke comforting words to the students and read poems before sending them home.
"This is no easy thing to deal with," said the mayor of Llinars, Martí Pujol. He said he was trying to get in touch with his German counterpart in Haltern.
"We want to go there," the mayor said.
"Myself and a representative of the school wish to go and offer our support. But they are the ones who have lost relatives, lost their children, so we'll wait for them to come back to us on how we should proceed on this." (© Daily Telegraph, London)