Michelle Williams gets back to work

Brave Michelle Williams gets back to work, shooting scenes for a new movie just days after Heath Ledger was laid to rest.

The actress was spotted in New York today filming drama Mammoth. The set - in trendy SoHo - was just streets from the apartment where Heath died last month.

Williams, 27, was seen shooting inside the Evolution store, which sells exotic bones and medical equipment. Cameras caught her walking by a skeleton.

An insider said: "The mood on set is pretty sombre.

"Everyone respects Michelle's professionalism in going back to work so soon."

An onlooker added: "She looked upset - as though she had a lot on her mind."

The body of Ledger, 28, the father of Williams' two-year-old daughter Matilda, was found in his New York loft on January 22. The death was ruled an accidental drug overdose. The couple split last year.

Williams was in Sweden shooting Mammoth when she learned of Ledger's tragic death.

She was pictured over the weekend frolicking in the surf with other mourners at a wake to say goodbye to the Brokeback Mountain actor.