TAINAN, Taiwan — Sophisticated sensors deployed at the site of a 17-story apartment complex that collapsed during a predawn earthquake Saturday here in southwestern Taiwan detected faint signs of life Sunday, including occasional cries, from some of the 119 people the authorities believed were buried deep under layers of rubble.
Rescue workers tried to reach them through the shattered remains of elevator shafts and through underground water pipes that went through the area, but were unsuccessful, said Chen Mei-ling, the city's secretary-general.
"We don't want to use big drills to get down there because we might kill people," Chen said in an interview Sunday night. So the debris field, the size of a large city block, had been divided into four areas, and large backhoes had begun trying to carefully remove the tangled layers of concrete, reinforcing steel bars and tiles.
Tainan authorities said in a statement late Sunday that 32 bodies had been recovered from the apartment complex ruins and that two people elsewhere in the city had also died in the quake.
Chen said an additional 99 people had been admitted to hospitals, and 376 had been treated for minor injuries and released.
Rescue workers were mainly using infrared sensors to locate people under the rubble, supplemented with metal detectors and fiber optic cables to help them navigate the buried terrain.
Prosecutors had begun reviewing the construction and engineering of the collapsed building, while the city government had retained its own team of professional engineers to analyze the structure, said Chen, the city's fourth-highest official.
"In this earthquake, it was just this building that collapsed, so it was definitely a problem with its construction, many people in town are saying," she added.
City leaders had initially hoped that the collapse of the complex had resulted in few deaths because they had found 10 bodies at the site and were able to account for all of its 256 registered residents.
But those hopes faded Sunday as investigators and officials learned that more than 100 young people, many of them students at nearby Kun Shan University, had been renting back rooms and interior apartments in the complex and had not been seen since the earthquake, said Liu Shih-chung, deputy secretary-general of Tainan.
Before its collapse, the complex resembled a single, U-shaped structure. But it was built as nine connected blocks. The middle of the U collapsed while the two wings stayed largely intact as they fell sideways and on top of the pulverized remains of the middle section.
The two wings were occupied predominantly by permanent residents, many of whom were able to escape.
Permanent residents and the authorities were unaware during the day Saturday that many people had been in the middle of the building, underneath the wings. But Liu said in an interview that evening that rescuers would work through the night to investigate the ruins, in case anyone was still inside. There was no sign Sunday morning that the rescue effort had ever slackened before the authorities realized that many temporary residents had been in the building.
Li Nien-tzu, 27, a restaurant worker, heard the building collapse just before 4 a.m. Saturday and quickly ran over, wearing only cotton sandals, and began crawling into holes in the facade once filled by windows.
She said she ended up leading or helping carry 13 people from the building, although several had fatal injuries. "Outside the building, it looks quite complete," she said. "But when you get inside, you have to descend inside with a rope. I held three children, and they were dead."
A series of minor aftershocks prompted the authorities to use steel beams and heavy equipment to prop up one edge of a fallen wing of the building, fearing that it would collapse and crush survivors and rescue workers inside.
At the edge of the rescue operation Sunday morning, Hsu Xiu-xiang, 52, a factory worker who had driven with her husband from northernmost Taiwan, waited for word of their son, Hsu Zhihua, a junior in electrical engineering at Kun Shan University.
Fighting back tears, Hsu described how her son had told her earlier in the week that he might return home Friday but decided to stay one more day to earn extra money in his job as a waiter.
After his shift Friday, Hsu Zhihua went with his three roommates and one roommate's girlfriend to a birthday party at a karaoke bar until just before the earthquake struck. One roommate then left for his hometown, so was able to tell Hsu Xiu-xiang later by phone what had happened after the rest of the group, including Hsu Zhihua, went into the apartment building.
"He's a very good kid. He's very sweet, and he actually studies and at the same time had a part-time job," Hsu Xiu-xiang said. "I was really looking forward to seeing him come home. It has been a long time."
Rescue workers from 16 cities were at the site Sunday night, but they did not have the kind of equipment sometimes used in colder climates to pump warm air underground and protect individuals trapped there from hypothermia.
"We still need to improve in this respect," Chen said. "It's usually pretty warm here, but the past two weeks it has been really cold."