Forecasters warned more rain and flash flood risk is expected on July 15 after storms flooded out roads the day before.

New York and New Jersey flooding shut down the NYC subway system, closed roads, and delayed and canceled flights as heavy rains swept across the Northeast Monday night.

More than 50 million Americans throughout the Northeast are under flood watches on Monday, with a significant risk of flash flooding in some areas. Flash flood warnings have been issued for cities including New York City, Newark, New Jersey, and Arlington, Virginia -- including the Reagan National Airport -- through Monday evening.

Storms prompted flash flood warnings across the New York City metropolitan area Monday night, with photos showing severe flooding across the city and in parts of New York state and New Jersey.

Two people died in New Jersey after their car was swept away. Public transit was largely running normally on Tuesday morning, hours after water flooded subway stations and damaged highways.

Footage shows wooden slats from the home on the ground with other debris. The blast took place around the same time heavy rainfall hit the northeast.