NEW YORK (AP) — The rough landing of a Delta jetliner at New York City's LaGuardia Airport in a driving snowstorm just minutes after the runway had been plowed has raised questions about when airports should close runways due to snow or ice.

Six people were hurt when the plane skidded off a runaway at midday Thursday and crashed through a chain-link fence, its nose coming to rest just short of the roiling waters of an icy bay.

The plane was removed with cranes overnight and taken to a hangar, the Port Authority of New York and New Jersey, which runs the airport, said Friday.

The affected runway was reopened at about 10:30 a.m. Friday, according to Port Authority spokesman Joe Pentangelo. The airport's other runway was reopened about three hours after the accident.

There's no rule about how much snow or ice leads to a runway closing. Instead, the Federal Aviation Administration requires airports to measure runways during winter storms to assure planes can safely brake: A specially equipped vehicle races down the runway with a computer checking braking action, and if the runway fails the test it must be closed.

The runway had been plowed minutes before, and two other pilots had reported good braking conditions, said Patrick Foye, executive director of the Port Authority. It appeared the pilot did everything he could to slow the aircraft, he said.

The National Transportation Safety Board said it was sending an investigator to retrieve the plane's flight data and cockpit voice recorders and to document damage to the plane.

LaGuardia, known for its disconcertingly close proximity to the bay, is one of the most congested airports in the United States. It's also one of the most difficult at which to land: Its close proximity to three other busy airports means pilots have to make a series of tight turns to line up with its runways while also going through their landing checklists.

LaGuardia's two runways are "reasonably short" but still safe, said former US Airways pilot John M. Cox, who's now CEO of consultancy Safety Operating Systems.

At airports with longer runways, pilots glide just above the runway and gently touch down. At LaGuardia, Cox said, "you put the airplane on the ground and stop it."

On Flight 1086 from Atlanta, passengers said there was a surreal calm as the plane bounced and slid off the runway, but some children started crying after it came to a stop. It was only then that everyone realized how close they had come to plunging into freezing saltwater.