British actor RUPERT GRINT was devastated by the murder of his HARRY POTTER co-star ROBERT KNOX - but credits the tragedy with giving him a new outlook on life.

Knox, 18, had just completed filming alongside Grint on forthcoming movie Harry Potter and the Half-Blood Prince when he was stabbed to death outside a nightclub in Kent, England last May (08).

The teenager's untimely passing had a big impact on Grint - because he had never had to deal with the death of a peer before.

But Grint reveals the tragic turn of events has inspired him to reflect on his own life.

He tells Britain's Live magazine, "Rob didn’t have a big role in the film but I got to know him well.

"Everyone on the set liked him. He was a funny lad, a proper character. Going to his funeral... that was a sad day. Rob was the first young person I knew who’d died.

"The enormity of his death hasn’t really sunk in for me yet. But I’ve learnt something from it in terms of counting my blessings, realising how lucky I am and the importance of making the right decisions for the future."