Torrential rain blamed for at least one death flooded subways and rail lines and delayed flights early Wednesday at New York's three major airports and thousands of commuters were stranded for two hours or more.

Wind and heavy rain toppled trees onto cars and streets, caused scattered power outages and left some shops shuttered and businesses struggling with shortages of workers.

Police Commissioner Raymond Kelly said officers had to use crowd-control tactics to keep the peace.

A woman who got stuck in an underpass was killed when her car was struck by another vehicle, Mayor Michael Bloomberg said. The mayor said buildings were damaged in parts of Brooklyn, including a roof ripped off a church.

• Monitor the situation in FOXNews.com's Natural Disasters center.

"I don't know that God had rush hour in mind when the storms hit," Bloomberg said at news conference in a Brooklyn neighborhood where the National Weather Service was trying to determine whether a tornado had struck.

All subway lines in the city experienced delays or diversions, and some rail lines to Grand Central Terminal and some rail routes from New Jersey into Manhattan were shut down for more than an hour.

"We are very much tied to mass transit, which is a system that is obviously vulnerable to natural events," Bloomberg said.

Passengers on one train to Grand Central were told they had to get off at a station in the Bronx and walk to a nearby subway station. Some trudged through the streets in drenched business suits, only to be told at the subway that those trains weren't running either.

Some commuters were understanding.

"It's nobody's fault. You see how hard the rain was coming down," said Mark Edwards, who tried to get on a subway in Brooklyn only to find that the line was flooded.

Others wondered how a strong but hardly record-breaking rainstorm could nearly bring the city to a halt.

"The weather is bad enough," said Vanessa Santiago. "But now I have to worry about getting into trouble for being late to work."

Elsewhere, 4 inches of rain fell in an hour in parts of Nebraska. Authorities in Surprise, 70 miles west of Omaha, reported the Big Blue River had overflowed and fish were swimming on the water flowing on state Highway 12.

More flood warnings were issued Wednesday in northern Illinois, where flooding a day earlier had forced dozens to evacuate their homes. The water-logged region already had been declared a state disaster area.

The rainstorms brought no relief from heat and humidity, and the weather service posted heat advisories from the Plains to the East Coast. The heat index, based on a combination of temperature and humidity, could reach 104 to 110 in parts of Kansas, the agency said. In New York's crowded streets, the index was expected to top 100.

North Carolina's largest electric utilities approached record demand as triple-digit temperatures across the Southeast strained electricity grids.

Coastal humidity at Charleston, S.C., was likely to make the expected high of 100 degrees feel more like 119, said weather service meteorologist Leonard Vaughan. On Tuesday, Charleston tied its record of 98 and Columbia tied its record of 102, Vaughan said.

In the Gulf states, utilities reported records electricity demand to drive air conditioners. Montgomery, Ala., hit a record high Tuesday of 101, the weather service said.

Visit FOXNews.com's Natural Disasters center for complete coverage.