Mira was taking a high school English final when the quake hit, flattening the school in seconds and killing her a week before her 16th birthday.
"We had planned to celebrate ... but she's gone," said her mother, Malina, weeping amid the wreckage where the barefoot body was found.
John Holmes, the UN's humanitarian chief, set the death toll at 1100, and the number was expected to grow. Government figures put the number of dead at 777, with at least 440 people seriously injured.
Wednesday's 7.6-magnitude earthquake started at sea and quickly rippled through Sumatra, the westernmost island in the Indonesian archipelago.
An eerie quiet settled over Padang late as workers called off search efforts for the night. Thousands are thought trapped under shattered buildings in the city of 900,000, raising fears of a significantly higher death toll when the debris is cleared.
"Let's not underestimate. Let's be prepared for the worst," President Susilo Bambang Yudhoyono said in the capital, Jakarta, before flying to Padang, a coastal city and West Sumatra province's capital.
President Barack Obama, who spent part of his childhood in Indonesia, pledged to support earthquake recovery efforts there as well as providing assistance in the South Pacific countries of Samoa and American Samoa, which were hit by a deadly tsunami on Tuesday.
Most of the confirmed deaths in Indonesia were reported in Padang where more than 500 buildings were severely damaged or flattened.
Where a mall once stood was a heap of concrete slabs layered like pancakes with iron rods jutting out. Police and army rescue teams used bulldozers, backhoes and electric drills to clear the wreckage in intermittent rain, or climbed the hills of rubble to dislodge pieces of concrete with bare hands.
Relatives of the missing gathered outside ruined buildings, hoping to hear good news. But mostly, the rescuers found bodies.
Occasionally, they saved lives.
A Singaporean, John Lee, was pulled alive from the Maryani hotel after surviving under the rubble for 25 hours. Rescue workers, responding to his cries for help, dug for 12 hours to free him. Lee suffered only a broken leg.
One of the hospitals in the town had collapsed completely while the state-run Djamil Hospital was partly damaged -- its walls cracked and windows broken. Staff at the hospital treated the injured in tents set up in the open. In another area, rows of yellow body bags were laid out in rows.
Mira, a sophomore, was taking an end-of-term English exam along with dozens of classmates at the Indonesia-America Institute when the ground shook so severely that the tremors were felt in neighbouring Malaysia and Singapore.
Her father Zul 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 said.
She said rescuers found their daughter's body much later, but her feet were bare.
"We are in a shock," sobbed Malina, wearing her daughter's brown veil and seeking other items to keep her connected to the girl. "We had planned to celebrate Utami's 16th birthday on October 7. Now I don't know what we will do."
Zul was more philosophical. "I regret I couldn't save her," he said, "but I have to accept that as her destiny."
The school building's construction was typical of the region, which is located in one of the poorest countries in the world. Most buildings are not made to withstand earthquakes, and even the tough ones were badly damaged in an earthquake in 2007.
There is virtually no enforcement of building regulations in Indonesia, a nation of 235 million people prone to natural and man-made disasters.
Indonesia sits on a major geological fault zone and experiences dozens of quakes every year. A 6.8 magnitude quake shook Sumatra on Thursday but there were no reports of deaths. Both quakes originated on the 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 3000 people died in the city of Yugyakarta.
SurfAid, a New Zealand-based medical aid group, said its programme director, David Lange, narrowly escaped death when he fled the Ambacang Hotel in Padang just minutes before it collapsed. At least 80 people were missing in the five-storey hotel, paramedics said.
"People are trapped and screaming for help but they are below huge slabs which will take heavy equipment to move," Lange was quoted as saying in a statement by SurfAid.
"I saw dozens of the biggest buildings collapsed in town. Most of the damage is concentrated in the commercial centre market, which was fully packed," he said.
Finance minister Sri Mulyani said the government has allocated $US25 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.
"This region has been damaged seriously, including its infrastructure," Mulyani said.
