A bird's eye view of the newly built Hengan residences for employees of Datong Coal Mine Group. Li Yi/ For China Daily

Those living close to the mines were not the only ones exposed to danger. Life was also precarious for residents living closer to the city center: "There was no heating, so every family relied on gas stoves during the winter. Almost every year there was a case of carbon monoxide poisoning in the neighborhood because the stoves weren't used correctly or hadn't been properly maintained. Some people died," said Chen Huaiyu, who lived in a bungalow in the old city for 58 years.

Chen shared a bed with his two younger brothers and two younger sisters until he was 18. Their parents also lived in the same 23-sq-m room. When Chen married in 1978, the family built a 6-sq-m wedding room in the already overcrowded courtyard.

"Every family tried to seize any free space available to build a room, which was quite understandable because of their living conditions. However, it made the street pretty narrow and if there had been a fire, it would have resulted in a horrible disaster."

Old habits die hard

While the families were thrilled to move to their new homes, some old habits can't be changed overnight.

Bai Yuwen had problems adjusting to a sit-down toilet. He had never used one before he moved into his new apartment five years ago.

"I never thought about it until I moved. It really took me months to get used to it," he said, with a wry smile.

Gao from the property management company said that at first it was hard to collect payment for services, such as keeping the area clean and litter-free, security guards and other items. The people had never paid for security guards when they lived in the mining zone. And garbage was simply thrown out the windows and left on the street.

"Things are much better now. Some of these people have waited almost their entire lives to live in a new home. We just need to give them a little time to adjust to this new life," he said.

Contact the reporter at tangyue@chinadaily.com.cn

Yang Wanli contributed to this report.