An aerial video from the rescue service shows several cars and a truck that stood near where the viaduct collapsed. A man from one of the cars closest to the falls stood up and held his arms up to the traffic to warn other drivers.
Giovanni Toti, governor of Liguria, said a landslide caused the collapse. The rescue service used dogs in the search for possible victims in the two-meter-high mud, but according to local media, no one was injured.
The highway is in the same region where 43 people died in 2018 after a bridge collapsed in Genoa during a rainstorm.
See more in the clip above.