In pictures: Alps plane search operation resumesPublished25 March 2015Shareclose panelShare pageCopy linkAbout sharingImage caption, A search and recovery operation has resumed in the southern French Alps after Tuesday's crash of a Germanwings plane with 150 people on board.Image caption, Members of the emergency services met at dawn to start the work to recover the crash victims and the remains of the Airbus A320.Image caption, Officials warn the operation could last for days in a remote mountain ravine between Digne and Barcelonnette.Image caption, French firefighters gathered outside the gymnasium in Seyne-les-Alpes where relatives and officials are due to pay tribute to the victims. French President Francois Hollande, German Chancellor Angela Merkel and Spanish Prime Minister Mariano Rajoy are expected to visit the crash scene later.Image caption, Sixteen teenagers on a Spanish exchange programme were among those on board the flight. The group, and two teachers, were from Joseph-Koenig school in Haltern, western Germany. A poster reading "Yesterday we were many, today we are alone" has been placed in front of a memorial of flowers and candles near the school.Image caption, Students were sent home for the day, but some returned to lay flowers and comfort each other. Most of those who died from the school were girls aged about 16, an official told the BBC's Katya Adler.Image caption, "This is the worst thing imaginable," the town's Mayor Bodo Klimpel said at an emotional media conference. He said the school would still open on Wednesday, but instead of normal lessons there would be "an opportunity for the pupils to talk about this terrible [tragedy] and begin to process this".Image caption, Burning candles and pins of German airlines Condor, Germanwings and Lufthansa were placed by crew members in commemoration of the victims outside the Germanwings headquarters at Cologne-Bonn airport.Image caption, Footage shot from a helicopter on Tuesday showed small plane parts scattered on the rocky mountainside. "The site is a picture of horror," German Foreign Minister Frank-Walter Steinmeier said after being flown over the ravine.Image caption, "Everything is pulverised. The largest pieces of debris are the size of a small car," Gilbert Sauvan, president of the general council of Alpes-de-Haute-Provence, told the Associated Press.Image caption, Using helicopters, a recovery team reached the site on Tuesday and later found the one of the two "black box" flight recorders - a key step in establishing what caused the crash. The interior ministry confirmed on Wednesday it was the cockpit voice recorder and had been damaged in the crash, although it could still provide information.Image caption, Finding the second box - the flight data recorder - will be a key aim of Wednesday's search operation. A team of police officers spent the night on the mountain, securing the site.