【明報專訊】THE MTR is undergoing a high-level shake-up. Five of its senior level executives, including Chief Executive Officer Lincoln Leong Kwok-kuen, have stepped down. However, its Chairman Frederick Ma Si-hang will remain in office until the end of this year when his contract expires. This has provoked much controversy. What has happened most recently shows that there is a serious issue about the integrity of the MTR's senior project executives. It is therefore appropriate to demand that they quit immediately. Even though the integrity of Ma Si-hang and Secretary for Transport and Housing Frank Chan Fan has not been questioned, Ma's failure to pick the right man for the right job has already cost him his credibility, which he needs to lead the MTR. It would be better to let him go as soon as possible than to make him stay to watch over the transition period. The case of Chan is a bit different from that of Ma. Whether he should step down depends on the report of the independent investigation commission. However, government officials should at least apologise to the public and deeply reflect on why they have trusted the MTR so easily.