When cracks appeared in Xiao 's house he feared the worse . Xiao 's hometown , Jining , is one of China 's massive `` coal cities '' He watched many of his neighbors ' homes sink into the ground . The government has been trying to rebuild these houses Sinkholes devouring 20 million square meters of land here a year .
When cracks appeared in Xiao 's house he feared the worse . Xiao 's hometown , Jining , is one of China 's massive `` coal cities '' He watched many of his neighbors ' homes sink into the ground . Officials : Sinkholes devouring 20 million square meters of land here a year .