The President, who cut short a tour of South America to return to Germany, is attending a memorial service for the victims of the crash.
"As we are standing together, we are creating a precious bond of compassion and of mourning together," Gauck told reporters. "I wanted to mourn with them... I could hear the sobbing of children and families."
Haltern: Trauernde Schüler auf dem Weg zum Gottesdienst pic.twitter.com/DXahf0Rezq— michael engelberg (@engelberg_ms) March 27, 2015
The Joseph König Gymnasium (secondary school) in Haltern, North Rhine-Westphalia, lost 16 pupils and two teachers returning from a language exchange in Spain on the flight.
Haltern: Trauernde Angehörige versammeln sich vor der Kirche. pic.twitter.com/klDtPg9U8j— michael engelberg (@engelberg_ms) March 27, 2015
Meanwhile, the Bundesrat, Germany's upper house of parliament, held a minute of silence for those killed on Tuesday.
“We are deeply affected and shocked by this tragic accident,” Hesse minister-president Volker Bouffier said.
“We can't alleviate the pain of the relatives and friends, but we are with them in our thoughts and empathise with them.”