One commuter, Pete Chiaramonte, 41, who was on his way to work at a towing company in Brooklyn this morning, said he saw what he thought was the storm touching down at around 5.30 a.m. near the corner of 37th Street and 13th Avenue. “It was a funnel shape,” he said. “It looked kind of black and blue,” adding, “it was way up high and came right down on the roof of” a department store. “Pieces of the roof were all over the place. It was a big bang.”

Mayor Bloomberg said this afternoon that the city was being overwhelmed by a weather catastrophe that came in three parts: a blast of rain that flooded streets and railway systems, a vicious storm that tore through Brooklyn, and scorching temperatures that could be followed later today by even more rain.

“We expect very hot temperatures and perhaps some thunderstorms,” he said. “One of the concerns is that you have buildings without roofs and clearly more rain would do a lot more damage to those buildings.”

Image Waiting to board a packed crosstown bus on the Upper West Side. Credit... Richard Drew/Associated Press

“Let me caution everybody,” he added. “Please try to stay indoors if possible. We’ve opened a number of cooling centers, and 311 will tell you where they are.”

Many of the weather-related injuries were broken legs and cuts and scrapes caused by shattered glass and fallen trees. The woman who was killed this morning was driving through an underpass when her car got stuck. After getting out, she was struck and killed by another car. Mayor Bloomberg said the driver of the second car had a suspended license and was arrested by the police.

“Clearly, if we hadn’t had the rain storm, this woman wouldn’t have been there,” he said.

Even as city officials surveyed the damage and tried to clear away trees and debris throughout Brooklyn, it was still unclear precisely what had struck. John Christantello, a meteorologist with the National Weather Service office in Upton, N.Y., said the storm was “definitely one of the stronger ones we’ve seen,” and said it was unclear whether it had reached the definition of a tornado.