WATCH: We were on scene this morning of at least a 10 car pile up crash in Duluth. Duluth Police urge everyone to take it easy during the morning commute. | WDIO

At least four people were killed, and 30 vehicles were involved in a pile-up crash in Colorado on Tuesday. "There were heavy winds in the area at the time of the crash, blowing dirt, causing 'brown out' conditions," Colorado State Patrol said in a statement. "There was low to no visibility for motorists." | ABC7

What happens when you stage a motorway pile-up on purpose? We partnered with Channel 4 to help capture one of the most ambitious crash experiments ever filmed in the UK. ⚠️ Multiple cars, a 30-tonne HGV, and a full-speed collision, all recorded using dash cams and 100 cameras. 4 members of the public thought they were part of a motorway safety study… they had no idea what was coming. This is more than a stunt. It's a test of modern safety systems, real driver reactions, and what happens when thi