Liam Neeson has returned to work for the first time since his wife died. The grieving actor is back on the Canadian set of his upcoming movie "Chloe," which he was filming when Natasha Richardson was injured during a skiing lesson on March 16.

Liam has reportedly "thrown himself" back into work, but film sources say he is having trouble hiding his grief when the cameras are off.

Liam Neeson's wife is in a critical condition after being injured while skiing. Natasha Richardson - the daughter of actress Vanessa Redgrave and sister of Joely Richardson - was rushed to a hospital in Montreal, Canada, after reportedly sustaining a brain injury.

A representative for the film 'Chloe', which Liam has been filming in Toronto, said: "Liam Neeson left the Toronto set immediately to fly to Montreal upon news of his wife's accident."