HALTERN, Germany -- Lara Beer waited at the train station, looking forward to seeing her best friend Paula returning from a 10th-grade exchange trip to Spain. The train came but her friend was not on it.

"I just went back home," the 14-year-old told The Associated Press on Wednesday, wiping tears away under her red-framed glasses. "Then my parents told me Paula was dead."

Sixteen high school students and two teachers in the western German town of Haltern were among those killed when Germanwings Flight 9525 from Barcelona to Duesseldorf crashed Tuesday in the French Alps.

The crash has sent shockwaves through Haltern, a rural town 80 kilometres (50 miles) northeast of Duesseldorf where it seemed everyone knew someone who had died.

Classes in Haltern were cancelled Wednesday but students were encouraged to come to the high school anyway, to be with classmates and talk with psychologists and other counsellors. Police erected barriers to keep cameras away as the students hugged and wept at a makeshift memorial of candles and flowers at the school's entrance.

The principal of Joseph Koenig High School, Ulrich Wessel, called the loss of 16 of his students and two teachers -- one who had just gotten married and another who was soon to be -- a "tragedy that renders one speechless."

"I was asked yesterday how many students there are at the high school in Haltern, and I said 1,283 without thinking. Then had to say afterward, unfortunately, 16 fewer since yesterday," he said. "That's just terrible."

The 16 students were chosen from a large group who wanted to go on the weeklong exchange trip, said town spokesman Georg Bockey.

"Some of those who were previously disappointed are now probably relieved, though totally devastated," he reflected.

Seventy-two Germans, some 51 Spaniards, and people from Britain, the United States, Australia, Japan, Israel, Turkey, Denmark, the Netherlands and eight other nations are believed to be among the 150 on board who died.

The dead also included three generations of one Spanish family -- a schoolgirl, her mother and grandmother, according to their town outside Barcelona.

At the school in Haltern, a hand-painted sign on an outdoor pingpong table read: "Yesterday we were many; today we are alone," with 16 white crosses painted underneath.

Beer was among a group from a neighbouring school who came to offer support to the Joseph Koenig students.

"We're all talking with each other. The atmosphere is indescribable," she said. "You just can't believe that your own friend is gone."

Stefanie Gabler tried to take her five-year-old daughter Milena to the memorial so she could add two candles and a hand-drawn painting, but said they were mobbed by TV cameras.

"They were coming from all sides. I even tried to sneak in through the back entrance but police wouldn't let me," she said.

The students had been returning from Llinars del Valles, a small Spanish town northeast of Barcelona.

Yassine Heddadi, a student in Llinars del Valles, said only days ago he was having dinner with nine of the Germans in his brother's restaurant, eight girls and one boy, chatting about soccer and other things.

"It was a lot of fun. We had a lot of laughs," the 17-year-old said, recalling one German girl ribbing him that her favourite soccer team recently upset his club, Spanish powerhouse Real Madrid, in the Champions League.

He said he didn't believe the terrible news at first.

"I was in shock," he said.

Heddadi was one of scores who attended a memorial in the Spanish town, which held a minute of silence for the victims.

"This has been a big blow," said 18-year-old Geronimo Gonzalez, whose sister had done the exchange program in Germany and been taught by one of the Haltern teachers who was killed. "It's tough to talk to the other kids, because there's no going back."

In Barcelona, the Liceu opera house held two minutes of silence at noon in honour of two German opera singers -- Oleg Bryjak and Maria Radner -- who took the doomed flight after performing at the theatre last weekend.