Taiwan's biggest earthquake in at least 25 years killed nine people Wednesday and injured about 1,000, while 50 workers travelling in minibuses to a hotel in a national park were missing.Some buildings tilted at precarious angles in the mountainous, sparsely populated county of Hualien, near the epicentre of the 7.2 magnitude quake, which struck just offshore at about 8 am and triggered massive landslides.The city's mayor, Hsu Chen-Wei, said all residents and businesses in buildings that were in a dangerous state had been evacuated. Demolition work was beginning on four buildings, the mayor said. The power of the quake was captured live as news anchors delivered their bulletins, steadying themselves against giant screens as their sets swayed and lighting rigs rocked back and forth overhead. The earthquake hit at a depth of 15.5 km, as people were headed for work and school, setting off a tsunami warning for southern Japan and the Philippines that was later lifted.Video showed rescuers using ladders to help trapped people out of windows. Strong tremors in Taipei forced the subway system to close briefly, although most lines resumed service.Contact has been lost with 50 workers aboard four minibuses heading to a hotel in a national park.The government put the number of injured at 946.The White House said the US stood ready to provide any assistance necessary.Taiwan's air force said six F-16 fighter jets had been slightly damaged at a major base in the city.In Japan, the weather agency put the quake's magnitude at 7.7, saying several small tsunami waves reached parts of the southern prefecture of Okinawa.