Hopes of finding more survivors from the rubble of a collapsed commercial building in central China faded Monday, at the end of a 72-hour "golden" rescue period identified by authorities.

The building in Changsha city, Hunan province -- which housed apartments, a hotel and a cinema -- caved in on Friday, sparking a massive rescue effort with hundreds of emergency responders.

There has been no official confirmation of any rescues since a seventh survivor was pulled from the rubble on Sunday afternoon, leaving at least 16 people authorities have identified as trapped. No contact has been established with 39 others.

Changsha mayor Zheng Jianxin had said the government would "seize the golden 72 hours for rescue", a window that closed Monday afternoon.
The seventh person was rescued more than 50 hours into the search effort, according to state broadcaster CCTV.

A one-meter-thick wall had separated the survivor from rescuers, who located her after detecting signs of life at the spot on Sunday.

Changsha police said nine people -- including the building's owner and a team of safety inspectors -- were detained Sunday in connection with the accident.

Authorities alleged that surveyors had falsified a safety audit of the building.

More than 700 first responders were dispatched to the scene of the disaster, which left a gaping hole in a dense streetscape.

State media on Sunday showed firefighters -- backed by a digger -- cutting through a morass of metal and sheets of concrete, while rescuers shouted into the tower of debris to communicate with any survivors.

President Xi Jinping had on Saturday called for a search "at all cost" and ordered a thorough investigation into the cause of the collapse, state media reported.

Building collapses are not uncommon in China due to weak safety and construction standards, as well as corruption among officials tasked with enforcement.

In January, an explosion triggered by a suspected gas leak brought down a building in the city of Chongqing, killing at least 16 people.