The horrifying bus crash on Tuen Mun Road yesterday dealt another tragic blow to Hong Kong at a time when many must have felt we had already endured as much suffering as we could bear. Coming in the wake of the terrible loss of life inflicted by Sars, the sense of grief felt by the community is all the more acute. Our thoughts are with those who are injured and the relatives of the 21 people who died. While the Sars outbreak raised searching questions about our health service and its ability to cope with a crisis, the disaster, in which bus 265M plunged off the busy highway and into a ravine, has raised fresh concerns about the safety of public transport. The question that many people were asking, as they watched harrowing television pictures of the scene, was: how could this happen here? At a time of much soul-searching over our political arrangements and the performance of the administration, here is a reminder, on a more everyday level, of the importance of good governance. In our modern, developed city in which the vast majority of our 6.8 million people depend daily on public transport, it is disturbing that such a tragedy could occur. Every effort must now be made to prevent such an accident recurring. The causes of the crash are still being established and it would be premature to try to draw too many conclusions. But the double-decker bus appears to have collided with an articulated truck before smashing through a roadside safety barrier and toppling over the edge. The driver of the lorry has been arrested on suspicion of dangerous driving. One area which should be looked into is the effectiveness of the roadside barriers. As long ago as 1988, concerns were being raised in the local district council that the barriers were inadequate. While they comply with the top British safety standards of the time, higher and stronger barriers are used in Hong Kong for other stretches of road which pass over residential buildings or railways. The issue was raised again in 1999, but it appears the expense involved in upgrading the barriers was considered prohibitive. In the light of yesterday's crash, this may turn out to have been a costly decision in terms of lives. It is a particular concern as the barriers involved are used all over Hong Kong on our many sections of elevated highway, along which double-decker buses travel every day. While cost implications are always a factor to be considered, a tragedy on the scale of this one should remind all concerned that safety must come first. The police investigation would have been helped if pictures from cameras providing a live Transport Department webcast on traffic conditions had been recorded. They would have captured the accident. This is another matter which should be reviewed. On a more positive note, the emergency services should be commended for the speed with which they reached the scene. A new government helicopter was put to good use and a temporary mortuary employed for the first time. Chief Executive Tung Chee-hwa can also take some credit for hurrying to the crash scene and visiting victims in hospital. Road accidents are inevitable in any busy city, but in Hong Kong the risk is increased by the number of vehicles choking the roads. Also adding to the danger are the frequent examples of bad driving and speeding which makes road travel in the city a daily hazard. It is only five years since the last serious bus crash, in which five people died as a result of the driver going too fast. The police should step up action to punish those who flout the rules of the road. Yesterday's tragedy serves as another painful reminder of the work to be done to make Hong Kong a world-class city.