What is the announcement mainly about?

Attention, all passengers. The City Hall Subway Station is now closed due to flooding.(83)All subway trains on north- and south-bound routes have been halted. Passengers who are in City Hall Station are at present being assisted in leaving the building by emergency teams. We advise all commuters to take buses that will be running along both routes at approximately ten-minute intervals.(84)We estimate that normal operations at City Hall Station will resume in two hours.(85)We apologize for any inconvenience.