PORT-AU-PRINCE, Haiti (AP):

All rescuers saw of Saint-Helene Jean-Louis when they arrived at the collapsed University of Port-au-Prince building were the top of her head and her left hand.

It had been four days since a 7.0-magnitude earthquake levelled the building, one of hundreds destroyed in the most powerful natural disaster to hit the impoverished Caribbean nation in more than 200 years - but the 29-year-old student was still breathing inside a stairwell of the former four-storey structure.

She was surrounded by eight decaying bodies, one entwined with her own.

Rescuers from the Fairfax County, Virginia, Urban Search and Rescue team tore away through a few more layers, digging down and sideways to free her upper body. She was able to sip a little water.

Nearly 30 hours later, working in two shifts, they pulled Jean-Louis out of the building - still alive. She was able to say her name before being whisked away to an Israeli field hospital.

"To me, she's the hero of the group," said Fairfax County firefighter Richard McKinney.

"She had to have spent that first night by herself."

Other foreign and national rescue teams worked feverishly to get to survivors in the capital of Port-au-Prince. Late Saturday, American rescuers were trying to free three people trapped alive in the rubble of a suburban supermarket. They managed to shout back and forth with the survivors, and get them water, but had just started attempting to reach them.

"Contact has been very brief because they are still yelling through concrete slabs," said Joseph Zahralban, captain of a FEMA urban search-and-rescue team based out of Miami, Florida, that was taking part in the rescue effort.

"They are aware of the fact we are attempting to rescue them."

School teacher rescued

Mexico's Rescue Brigade, a group with mole-like tunnelling skills that located survivors after Mexico's deadly 1985 earthquake and in New York after September 11, pulled 35-year-old teacher Jean Baptiste Patrick alive from the rubble of the St Gerard Technical School on Saturday, according to an Associated Press photographer who witnessed the rescue. The brigade worked in coordination with Mexican federal police and the Mexican Navy.

On Friday, 18 members of the brigade pulled seven other survivors out from under collapsed buildings, said team coordinator Fernando Alvarez.

Israeli troops rescued the director of Haiti's tax ministry who was trapped in the ruins of his office building. Soldiers carried him out on a stretcher, checked his vital signs and declared him unhurt.

Emergency workers early Sunday pulled the co-owner of Hotel Montana from its wreckage. Nadine Cardoso, 62, was dehydrated but otherwise uninjured, said her husband, Reinhard Riedl. Rescuers who thought other people had survived emerged with an empty stretcher and explained there was no other sign of life.

Nearly 30 teams from around the globe were scrambling on Saturday to find and rescue the living, US Secretary of State Hillary Clinton told reporters in Port-au-Prince.

It was increasingly a race against time: Red Cross spokesman Simon Schorno noted that the critical 72-hour period for finding survivors "has past and ... these stories of people surviving are getting rarer".