sentences:  One week before the earthquake, 160,000 inhabitants were counted in the entire Messina commune.On 28 December, Messina was even more crowded than usual, due to the number of overnight visitors from outlying areas who had come to the city to see a performance of Giuseppe Verdi's opera "Aida", which had been staged the previous evening at the Vittorio Emanuele II theatre.About ten minutes after the earthquake, the sea on both sides of the Strait suddenly withdrew as a 12-meter (39-foot) tsunami swept in, and three waves struck nearby coasts.