Thessaloniki - Authorities in the northern Greek city of Thessaloniki evacuated an estimated 75 000 people on Sunday so army experts could defuse a 227kg unexploded World War II bomb found under a petrol station.The evacuation started at 07:00 (05:00 GMT). Police went house-to-house ringing bells and knocking on doors to remind people living within a 1.9km radius, mostly in the western suburb of Kordelio, to leave their homes.Bomb disposal experts started work at 11:30, 90 minutes later than planned, but defused the bomb in only 30 minutes, Central Macedonia governor Apostolos Tzizikostas announced.The bomb was now going to be taken to an army firing range.'Total success'"The first phase of the bomb disposal has been a total success," Tzizikostas announced. "There remains its removal from the site. Residents will still not be allowed in their homes, because the removal and transport contains dangers."Many people left the area in their cars, but some were bussed to schools and sports halls elsewhere in the city."We heard on TV that, if the bomb explodes, it will be like a strong earthquake," a worried Michalis Papanos, 71, told The Associated Press as he and his wife, Yiannoula, headed out of their home.Others, like 26-year-old Alexander Bogdani and his wife, Anna Bokonozi, left on foot. The couple, pushing a stroller with their toddler daughter, were going to a place about 1km from their home."They have warned us ... we are afraid for the child," Bogdani said.ShutdownThe city's main bus station was shut down, trains in the area were halted and churches cancelled their Sunday services. The city also booked a 175-room hotel where people with limited mobility and their escorts were taken on Saturday."This is the largest population move in peacetime. People must be calm and not panic," Central Macedonia governor Apostolos Tzitzikostas said.Among the evacuees were 450 refugees staying at a former factory, who were transported by bus to visit the city's archaeological museum.Army bomb disposal experts will attempt to defuse the bomb's detonator, and then transport it to an army firing range, where they will figure out what further steps to take, said army spokesperson Colonel Nikos Fanios.One resident says he recalls the day the bomb fell."The bombing was done by English and American planes on September 17, 1944. It was Sunday lunchtime," said Giorgos Gerasimou, 86, whose home is half a mile away.The Allies were targeting local German rail facilities, he said.Nazi Germany occupied Greece from 1941 until October 1944.