A surveillance video from Xingtai, Hebei caught two vans, and a car, seemingly levitating off the ground before falling back on the road, one rolling onto its side. Beforehand, the traffic was flowing normally.

The then-unexplained video went viral (in late 2015). Theories of what happened sprang up. From force fields or X-Men-like powers to a hoax or a earthquake, people were fascinated. The video was shared thousands of times and viewed more than a million. It appeared on media outlets like CNN, the Huffington Post and the Telegraph.

Taking a closer look at the right-hand side of the video, a road sweeper appears just before the minivan approaches the traffic lights. That's the key to the 'levitation.' A thick cable got wrapped around one of the road sweeper's brushes and essentially created a tripwire across the road way, causing the vehicles to lift and flip.

No one was injured in the accident. 

To view the video, visit, http://www.cnn.com/videos/world/2015/11/30/china-levitating-cars-mystery-solved-orig-sdg.cnn