Panicked subway passengers screamed "We're going to die!" when waves of smoke filled a New York subway tunnel Friday, killing one person and injuring 151 others.

In Boston, a light-rail car rammed into another that was unloading passengers at an underground station, injuring 33 passengers in the second rail accident this month in the city's Back Bay section.The New York accident during the morning rush hour in a tunnel linking Manhattan and Brooklyn apparently was triggered when melting snow caused an electrical short-circuit, according to fire and transit officials. The city got 7 inches of snow overnight.

"We really thought we were gone, that we wouldn't see New Year's," said Gertrude Hoyte, a 51-year-old Brooklyn resident who was on one of four trains trapped in the tunnel just after 9 a.m.

Passengers heard explosions and then saw smoke, first pouring into the tunnel and then into their trains.

Transit Authority spokeswoman Caren Gardner said it was unclear exactly how snow set off the incident, but it was possible that it fell onto the electrified third rail and caused an electrical cable to short.

The dead man was identified by Transit Police spokesman Al O'Leary as Peter Hagen, 35, of Smithtown. A spokeswoman for Long Island College Hospital said he was brought in in full cardiac arrest but a medical examiner would have to determine the cause of death.

It was unclear how many people were aboard the four trains, but Transit Police Capt. Michael Ansbro said 300 to 400 people were on the 10-car train that carried most of the injured.