Rescuers pulled a teenager alive from her collapsed college about 40 hours after a powerful earthquake devastated western Indonesia, while elsewhere they heard cries for help Friday from people trapped under a collapsed hotel.

The rare success reinvigorated frantic efforts to find thousands of people still missing after Wednesday's 7.6-magnitude quake that toppled hundreds of buildings in Sumatra, a heavily populated island in this impoverished nation where natural disasters are common.

The official death toll stood at 715, the Health Ministry's crisis center chief Rustam Pakaya told The Associated Press. One U.N. estimate said as many as 1,100 may have died.

Rustam said more than 2,000 people were injured and "thousands" missing based on reports from relatives, though he could not put a firm number yet on the missing.

Amid the grim landscape, rescuers found a reason to cheer: Ratna Kurniasari Virgo, 19, an English major sophomore, was found alive under the rubble of her college, the Foreign Language School of Prayoga. A conscious Virgo was pulled out Friday morning, 40 hours after the quake hit Sumatra at 5:15 p.m. Wednesday.

Amid excited shouts and words of encouragement to each other, rescuers pulled Virgo hands-first from a hole drilled in the debris. Her olive colored T-shirt almost spotless, Virgo was laid on a stretcher before being taken to hospital.

"She is fine, conscious and does not have any life-threatening injuries," said Nining Rosanti, a nurse, at the hospital.

Officials said a lack of heavy digging equipment made it nearly impossible to pry apart giant slabs of concrete from toppled buildings.

"Heavy equipment and rescuers are our priority," said spokesman Priyadi Kardono of the national disaster management agency. "We have to give them complete access to enable them to rush to the victims."

At the site of the former Ambacang Hotel in Padang city, rescue workers detected signs of life under a hill of tangled steel, concrete slabs and broken bricks of the three-story structure, said Gagah Prakosa, a spokesman of the rescue team.

"We heard some voices of people under the rubble, but as you can see the damage is making it very difficult to extricate them," Prakosa said, as a backhoe cleared the debris noisily.

The voices were heard 44 hours after the disaster, giving hope that many lives could still be saved.

The damage from the undersea quake was most extensive in Padang, a coastal town of 900,000 people and the capital of West Sumatra province.

Medical teams, search dogs, backhoes and emergency supplies, some of it given by other countries, were flown into Sumatra on Friday after Indonesia issued an appeal for international help.

"Please be patient," Indonesia's President Susilo Bambang Yudhoyono told the crowd of people whose relatives are missing, assuring them that the government was doing everything in its power to save lives.

But death appeared to be more pervasive.

Paramedics laid out dozens of bodies at the Dr. M. Djamil General Hospital, Padang's biggest, which also was partly damaged in the quake. The air was filled with frequent sirens from ambulances ferrying bodies.

Anwari, who uses only one name, burst into tears when asked who he was waiting for under the blazing sun outside the hospital.

"Don't ask me about my daughter... She is still missing," Anwari said, between sobs. "Please don't ask me ... it reminds me of her." He was too distraught to say anything more.

The crushed remains of the dead were beginning to decompose in the tropical heat and mass funeral arrangements were being made by families at local mosques.

With communications and power supplies still down in many areas, fuel was being rationed to focus on locating thousands still missing.

Twenty-eight tons of supplies, including water, medicine and basic food provisions, were flown into regional airports to be distributed to the needy. Aid workers handed tents to some of the tens of thousands of people made homeless, disaster management spokesman Kardono said.

Russia sent two planeloads of supplies, along with doctors and nurses to treat the seriously injured.

Also donating millions of dollars in aid and financial assistance were governments and charities of Australia, China, Germany, Japan, the European Union, Malaysia, Singapore, Switzerland and the United States, Indonesian officials said.

President Barack Obama, who spent part of his childhood in Indonesia, pledged to support earthquake recovery efforts there, as well as provide assistance to the South Pacific countries of Samoa and American Samoa, which were hit by a deadly tsunami Tuesday. The United States pledged $3 million in immediate assistance to Indonesia.

Among the dead was Mira Utami, a sophomore a week shy of her 16th birthday. She was taking an end-of-term English exam along with dozens of classmates at the Indonesia-America Institute when it collapsed.

Her father, Zul Elfrizal, rushed to the school, but it was already a heap of concrete when he got there. Still, he pulled at the slabs and managed to save two other children and an adult.

His wife, Malina, said rescuers found their daughter's body much later, but her feet were bare. Now, Malina was looking for her daughter's shoes — to preserve them as the last link with Mira.

The school building's construction was typical of the region. Most buildings are not made to withstand earthquakes, and even the tough ones were badly damaged in an earthquake in 2007.

Indonesia sits on a major geological fault zone and experiences dozens of quakes every year. Wednesday's quake originated on the same fault line that spawned the 2004 Asian tsunami that killed 230,000 people in a dozen nations.

Wednesday's quake was the deadliest since May 2006, when more than 3,000 people died in the city of Yogyakarta.

Finance Minister Sri Mulyani said the government has allocated $25 million for a two-month emergency response. She said the earthquake will seriously affect Indonesia's economic growth, because West Sumatra is a main producer of crude palm oil.