ROME, Jan. 18 (Xinhua) -- Italy on Thursday marked the first anniversary of a deadly avalanche that killed 29 people at the Rigopiano Hotel, a luxury mountain resort in the central Abruzzo region.

On January 18 last year, a 120,000-ton mass of snow sped down a mountain at about 100 kilometers per hour and tore into the four-star hotel, located at altitude of 1,200 meters.

Most of the fatal victims were subsequently found in the entrance hall of the hotel, where they had gathered to wait for a snow plough to dig them out of the snowbound resort so they could leave.

A total of 11 survivors -- including four children -- were eventually dug out of the rubble and snow.

Some of the 29 victims were instantly crushed to death while others were trapped and died of hypothermia and asphyxiation.

Commemorations began with authorities laying a wreath in the presence of families and local residents at the entrance to the remains of the hotel.

Poetry readings and a classical music concert with tenor Piero Mazzocchetti took place at a sports center where rescuers were based during the ordeal a year ago.

Italian President Sergio Mattarella and Prime Minister Paolo Gentiloni are scheduled to meet with the victims' families next Monday, ANSA news agency reported.

A total of 23 suspects, including several officials, are being investigated over the delays in clearing the only road connecting the hotel to town and in the subsequent rescue effort.

Italian prosecutors are trying to ascertain why distress calls from the hotel were initially dismissed, why the snow plough didn't arrive until long after the avalanche hit, and whether safety procedures were followed.