The 27-year-old star left Sweden yesterday (January 23), where she was filming the Lukas Moodysson drama, Mammoth.
Williams arrived in New York yesterday with her daughter. The two are now back in their Brooklyn apartment. A source told People magazine that Williams is "devastated" over the death of her boyfriend of three years, and the father of her child.
For now, no details have been released about a funeral for the famous 28-year-old actor. A second autopsy will be conducted to determine the cause of death.