Terrifying footage has emerged of the moment an illegal migrant driving a huge semi-truck caused a tragic crash which left three people dead.

Harjinder Singh - who obtained a commercial driver's license in California - was charged with three counts of vehicular homicide for the horrific crash in Florida last Tuesday.

Video from inside his enormous semi-truck shows the moment he casually began performing a U-turn on a highway, failing to consider other cars on the road traveling at speed.

As he took up the entire highway, a minivan crashed directly into the side of the truck, unable to break quick enough to prevent the tragedy.

Two passengers were killed on impact, while the driver was rushed to hospital and later declared dead.