HALTERN AM SEE, Germany — Even after word began to spread around the Joseph-König-Gymnasium on Tuesday morning that a plane on its way from Barcelona to Düsseldorf had gone down in France, Ulrich Wessel, the principal, kept alive hope that his students were not aboard that aircraft.

Yes, a group of 10th-graders from the school — 14 girls and two boys, traveling with two teachers — were flying home to Düsseldorf from Barcelona that morning after a weeklong exchange program. But, Wessel recalled Wednesday, he reasoned that there were lots of planes flying that route, especially when many German schools have spring break.

Then he heard it was a Germanwings flight, the same airline his students were scheduled to take. Still, Wessel said, he did not give up hope. Maybe it was a different Germanwings flight, he thought. Or maybe, he thought in growing desperation, the students had missed the flight.

Around 2 pm Tuesday, Wessel received the official confirmation from the prime minister of the state of North Rhine Westphalia. The Joseph-König students, 15 and 16 years old, had been aboard. It fell to Wessel to tell the parents, many of whom had come to the school looking for news.

“I went to the parents,” said Wessel, a tall man with tousled blond hair who was wearing a dark suit and tie Wednesday. “I can only say this is something I don’t want to experience more than once in my lifetime.”

Visibly shaken, his eyes red, Wessel described the events of the previous 24 hours at a news conference and in interviews afterward. As much as anyone, he embodied the shock that has gripped this town of orderly brick and stucco homes in northwestern Germany since the crash of the Germanwings flight Tuesday in the French Alps.

The shock was visible everywhere. At the St. Sixtus Roman Catholic Church, which dominates the centre of Haltern am See’s old town, mourners trickled in Wednesday morning to light candles below a large crucifix. The crucifix is traditionally placed in front of the altar every Good Friday, but was brought out early this year.

In the surrounding pedestrian zone, typical of small German cities with their cobbled streets and modest shops and cafes, virtually no one was smiling. Television crews that have descended on the town since Tuesday tried, mostly in vain, to interview townspeople.

Officials of the community of 38,000 people said they had been inundated with condolence messages from around the world.

“All I can say is that the whole town is in deep mourning,” said Bodo Klimpel, the mayor. “We can hardly grasp what has occurred.”

Angela Merkel, the German chancellor, also called to offer her sympathies, Klimpel said.

Students were dismissed about 1 pm Tuesday, before it was certain that their classmates were aboard the plane that crashed, Wessel said. They were merely told that they should not be rejoicing in the afternoon off — something terrible had happened.

On Wednesday morning the students gathered in the school, a three-story concrete building guarded by the police since Tuesday, to mourn. Some cried and others were silent, said Sylvia Löhrmann, a former teacher and the education minister for North Rhine-Westphalia, who spoke at the memorial.

Löhrmann said at a news conference that she told the students, “There is no power in the world that can take away the pain suffered by the families and friends. We can only share their grief.”

The police cordoned off the school Wednesday with red and white tape and plastic barriers. In front of the school, a hand-painted sign read, “Yesterday we were many. Today we are alone.” A small boy, holding a woman’s hand, added a bouquet of red roses to the flowers and flickering candles covering the front steps of the school.

Officials said that several dozen professional counselors had come to the town to offer psychological support to parents, students and teachers. Officials of Germanwings, a subsidiary of Lufthansa, as well as the German and French authorities, were arranging for family members who wished to visit the crash site to do so, though it was not certain when that would be.

Both of the teachers who died were young women, one of whom had married in October and another who planned to marry soon, Wessel said. There were far more students who applied for the one-week exchange program than could be accommodated, he said, so the 10th-graders were chosen by lottery.

“I sent them on this trip,” Wessel said, speaking to several reporters in Haltern am See’s town hall after the news conference. “I signed the forms.”

“I don’t feel guilty,” he said. “But … it’s very hard to bear.”

Asked if the school would continue the exchange program, with the Spanish town of Llinars del Vallès, Wessel said it was too soon to say.

“I’m asking myself how I can get through the next few days,” he said.

But he added, “Class trips are part of school. Statistically, flying is still the safest way to travel.”

“Though,” he said, “the statistics failed in this case.” – NYT/nst