A mentally disturbed man smashed a car with a hammer on a highway in Goa without any provocation while the vehicle's occupant was on way to the Dabolim airport, a police official said on Sunday. The incident took place around 11.45 am on Saturday near O'Coqueiro junction in Porvorim area following which the man was detained, police inspector Anant Gaonkar said, adding that the attacker had a history of mental illness. A video of the incident later went viral on social media platforms.