The sinkhole appeared at 2:30 p.m. as people were walking around minding their own business on the sidewalk, according to local media reports. Then, without warning, the ground opened, leaving a massive 100-square-foot pit and swallowing several people in a matter of seconds.
Two people extracted from the pit — a recently married couple — died in the hospital soon after the incident. Bodies of two more people were discovered buried under some 30 feet of rubble, CNN reported.
"When we arrived, the caved-in area was not big, which only covered [6½ feet] both in length and depth. But during the rescue process, it collapsed again, causing another [6½-foot] sink," said Gao Mingyue, a fire service official, according to New York Post. "Firefighters at once evacuated while doing the rescue work."
What's worse, the underlying infrastructure was severely messed up by the tragedy. High-voltage cables and gas pipes were damaged and became entangled with each other.
"Given what we found in the hole, cables are crossed in a mess, including two high-tension lines, weak electric wires and gas pipelines," Gao said.
As if that were not enough, the layer of soil where sinkhole appeared is just too thick for the available excavators to handle.
"We had to move excavators to a lower place and we now have two large excavators digging out soils so that we can stand on a lower place and use the long arm excavator to dig deeper," Gao added.
As of now, the exact cause of the sinkhole remains unclear, but they usually appear because of underground erosion, CNN notes.