Passengers clung desperately to the wings and tail of a sinking Chilean jetliner that skidded off a runway into icy waters near Cape Horn, witnesses said Thursday. Authorities said 20 died and 17 were injured.

One Texas survivor of Wednesday's crash described a frantic struggle to get out of the plane as water rushed in and drowned her husband and others inside, a relative said.Investigators were probing what caused the chartered jet, with 65 mostly American passengers on their way to an Antarctic cruise, to overshoot the runway while trying to land at Puerto Williams during a light rain.

The British-made BAe-146, a small four-engine jet, crashed into Beagle Channel off Navarino Island, about 1,500 miles south of Santiago and 60 miles north of Cape Horn, said the Chilean airline LAN.

A U.S. diplomat, Lawrence Kerr, flew to Puerto Williams early Thursday with an investigative group led by Chilean air force Cmdr. Hernan Barahona.

The Chilean navy said 20 passengers died, while the airline said 19 were killed. A list of the victims was not expected until later today. The seven crew members survived.

LAN said 17 people were "slightly injured" and were being treated at a navy hospital in Puerto Williams.

But Chilean press reports said two of the injured were in serious condition, including an elderly American woman who suffered a heart attack. LAN did not immediately comment on the reports.

Passengers grabbed onto the plane's wings and tail and waited for rescuers, while others tried to swim to the beach 150 yards away, reporters said.