People had to duck for cover when this 31-year-old building was demolished seemingly without warning.

The Oh MiZhonglian building in Changzhou, a city in east China, was torn down on Apr. 25 to make way for an upcoming subway line.

According to reports by the Yangtse Evening Post, traffic lights for the street facing the building turned red a minute before the 12-storey building collapsed.

The city reportedly closed nearby facilities like kindergartens and worksites before the demolition occurred, but some passers-by were not clued in.

In videos posted to Weibo, you can see terrified people on the street running from the collapsing building:

Holy...

The building was erected in 1986, and was once a landmark in the city.

The state-run Yangtse Evening Post said that notices were distributed around the area before the building collapsed.

The building had been gradually hollowed out, and machines had punched holes on each floor on the building during the past two days, weakening the building's structure until it collapsed on its own. No dynamite was used during the demolition.

Still, scenes of people running away from dust clouds has got Weibo users up in arms.

"Wow, they really didn't close the roads?" said one user.

"They really didn't close the surrounding areas? This is really scary!"

"What if they miscalculate and it collapses on the wrong side?" another user asked.