Hundreds of mourners attended the national memorial service in Cologne's landmark cathedral on Friday, including German President Joachim Gauck and Chancellor Angela Merkel.

Gauck, the main speaker, told the service the nation was still in "enormous shock" over the tragedy of flight 4U 9525, which crashed into the French Alps on March 24, killing all 150 people on board.

"Since this day, nothing has been what it was for these families and friends" of the victims, Gauck said. "Something was destroyed that can never be healed again in this world."

Some 1,400 people - including 500 victims' relatives - attended the ecumenical service, presided over by Cardinal Rainer Maria Woelki, who left Berlin to take over the Cologne archdiocese just last year.

"You are not alone in these hours of loneliness," he told grieving family members, encouraging them to take comfort in the crowds of people with them at the service. "Love is stronger than death."

Tragedy in three countries

The Germanwings crash has had a wide-reaching impact in western Europe. Most of the victims on board the ill-fated plane traveling from Barcelona to Düsseldorf were Germans and Spaniards. In his address to the congregation, President Gauck offered his thanks to the French people for their role in leading the rescue operation at the crash site in the south of their country.

"For this touching sign of friendship between our countries we are all most deeply grateful," the president, whose role is largely ceremonial, said.

French cabinet minister Alain Vidalies and Spanish Interior Minister Jorge Fernandez Diaz were also present at the service.

Deutsche Welle reporter Kate Brady was in Cologne, observing the proceedings on a big screen set up outside the cathedral. The service was also broadcast live on national German television.

A candle for each of the dead, including Lubitz

Across Germany, flags flew at half-mast, while buses and trains in Cologne stood still for a minute of silence as the cathedral service got underway. Inside the famous gothic structure, known in German as the "Kölner Dom," a choir sang hymns, while small wooden angels were put on the pews. The steps to the altar were covered with 150 candles - one for each person who died in crash, including co-pilot Andreas Lubitz.

Investigators believe Lubitz locked the pilot out of the cockpit before deliberately setting the plane into a rapid descent.

Referring to the decision to include a candle for Lubitz, Cardinal Woelki told Germany's "Bild" newspaper: "It's not for us to judge."

President Gauck also asked the congregation to remember the co-pilot's family. "On March 24 his relatives lost someone whom they loved and who leaves behind a hole in their lives - in a way that they find just as difficult to make sense of as all the other bereaved."

nm/msh (AP, AFP, dpa)