SHENZHEN, China — Rescuers searched for survivors in a sea of red mud on Monday, a day after dirt and construction debris engulfed dozens of buildings in this city in southern China, the latest of several man-made disasters in recent years to lay bare the perils of the nation’s rapid growth.

Hundreds of emergency workers used bulldozers and earth movers to search a 94-acre area in a city where some residents had for years worried that the dumping of debris so close to their homes was a crisis waiting to happen. The massive wave of earth buried or toppled 33 buildings, including apartments, worker dormitories and factories. As of late Monday, 81 people were still missing.

“Everyone was yelling, ‘Run, run,’ and I didn’t take anything except my baby,” Chen Qing said, as she nursed her 1-year-old son in a shelter for survivors set up in a nearby sports center. “I don’t know who’ll help us now. Everything in our lives has been left in the mud.”