Flash floods rage in Vermont, New York; 50 rescued by swift boat

Torrential downpours unleashed flash floods on the U.S. Northeast on Monday that washed out roadways, overwhelmed rivers, prompted 50 swift boat rescues and killed a woman who was swept away in front of her fiancé, officials said.

More than 13 million Americans were under flood watches and warnings from Eastern New York state to Boston and Western Maine to the northeast, the National Weather Service said in its forecast Monday, after storms that began over the weekend inundated rivers and streams.

Private forecaster AccuWeather estimated damages and economic loss at $3 billion to $5 billion, preliminarily, based on its own method of evaluation.

More than 1,000 flights to and from airports across the region, including New York's LaGuardia and Boston's Logan, were delayed or canceled on Monday due to the rains.

Amtrak suspended passenger train service between the state capital Albany and New York City after flooding damaged tracks, as did the Metro-North commuter railroad which shares some of the same track.