TAINAN, Taiwan (Reuters) - When an earthquake struck southern Taiwan in the early hours of Saturday, Chang Chun-jung thought it was all over.

Asleep on the 10th floor of the Wei-guan Golden Dragon Building in Tainan city - now the focus of rescue efforts - Chun-jung, 28, didn’t even have time to call out to his mother, sleeping in the same room.

“I opened my eyes, there were a few shakes and then everything collapsed,” he told Reuters from his hospital bed.

Once the shaking stopped, he checked that his mother was still alive and reached out in the dark to feel what was around him. He and mother had a pocket of space but were pressed down by heavy debris on top of them.

“Can anybody help?” he recalled shouting out for what seemed like an age.

Elder brother Chun-po, 29, who had been sleeping in another room, at first did not know who was shouting for help, and called out “who are you?”, before realizing it was his brother.

Chun-po was lucky though, and could feel a space above him and began to dig himself out with his hands. He kept climbing upwards, and as he got closer to the top he could feel the temperature getting colder.

But nobody could see him. He took a pole and started to wave it around above him and get the attention of the rescuers, who lowered a ladder to get him out.

Younger brother Chun-jung was worried though. While he had the pocket of space behind him so could breathe easier, his mother was hemmed in by debris.

“I spoke with my mother to tell her to save her breath, to allow air to circulate,” he said. “My mother had trouble breathing.”

Fortunately, his and his mother’s feet were sticking out of the rubble so they could be seen from outside.

The Wei-guan was the only major high-rise building in the city of two million people to have completely collapsed. Its lower storeys, filled with arcades of shops, pancaked on top of each other before the entire U-shaped complex toppled in on itself.

“Big brother please tell them to hurry up and rescue us. We almost can’t bear it any more,” Chun-jung said he called out to get things moving. Soon they were being pulled clear by the rescuers.

It was 6.30 a.m., nearly three hours after the quake, when Chun-po first emerged from the rubble. He knew the time because his brother’s alarm clock went off somewhere underneath the debris. All three are being treated in hospital for lacerations.

At least 38 people are known to have died in the building with more than 100 missing, likely dead.

Questions have been raised about the building’s construction quality.

Mother Hsu Bi-chi said she had had her suspicions the building had problems.

“The basement would always get wet after heavy rain,” Hsu said, adding the elevators would often be out of service.

Chun-po added: “We always wanted to move, but we couldn’t afford it.”