The Nobel Prize-winning mathematician, John Nash, has died in a car crash in New Jersey, USA.
He was 86.
Nash was travelling in a taxi cab with his wife, 82-year old Alicia, died when the taxi cab attempted to overtake a jeep on the New Jersey Turnpike.
It's understood that the cab hit a guard rail, with the driver losing control over the vehicle.
Russell Crowe famously portrayed Nash and his struggles with schizophrenia in the 2001 film, A Beautiful Mind.
The actor took to Twitter early today to express his sadness at the passing of a mathematics giant.
Stunned...my heart goes out to John & Alicia & family. An amazing partnership. Beautiful minds, beautiful hearts. https://t.co/XF4V9MBwU4
— Russell Crowe (@russellcrowe) May 24, 2015
Nash won the Nobel Prize in 1994 for his work on game theory, developing the Nash Equilibrium.
The film based on his life, A Beautiful Mind, won four Academy Awards, including Best Picture and Best Adapted Screenplay.