Heavy rain in New York City

Residents watch as workers attempt to clear a drain in flood waters, September 29, 2023, in the Brooklyn borough of New York. (AP Photo/Jake Offenhartz)

New York City and its adjoining areas have been brought to a standstill after a bout of torrential downpours triggered flash flooding, disrupting subway service, inundating ground-level apartments and delaying flights.

Authorities declared a state of emergency and warned people to remain indoors as almost eight inches (20cm) of rain fell in some parts of the most populous city in the US. Another few inches could fall in the region before the storm system pushed out to sea later on Friday, forecasters said.