Talking about underground tunnels for MRT. The City hall MRT is just under Singapore River, Raffles station, if I am not wrong is below one of the Kallang river tributaries. There may be others which are under certain rivers, because Singapore has many rivers and tributaries running everywhere.
My concern is, should an explosion occurs underground, near or at an underground station, below a river, will our whole underground MRT network be flooded ? Are there any precautions taken, if incooperated, what are they and where ?