Police have said it was lucky no one was killed after a breeze block was dropped through the windscreen of a van from a bridge in Barnstaple.
The middle of the Enterprise van was smashed when the block was deliberately dropped from the bridge over the A361 between Whiddon Valley and the Bishops Tawton roundabout at 3.13am on Monday, September 30.
Miraculously, no one was injured.
Police have launched an immediate appeal to find the culprits and believe somebody must know who did this.
North Devon Superintendent Toby Davies said: "It must have been absolutely terrifying. That's why we are taking it so seriously, because it's already a serious incident but could have been a lot worse and somebody could easily have been killed in this situation.
"I have a feeling that somebody out there knows something, so please pass it on to us."
Speaking on the bridge in a video posted on Twitter, roads policing Sergeant Dave Thubron said it was a severe incident with potentially serious injuries, calling it 'attempted GBH or possibly attempted murder'. See his full video below.
Anyone who has any information is asked to call 101, quoting log 43 of 30/09/19 or email email@example.com .