Friends and celebrity colleagues – including Tom Cruise, Sienna Miller, Ellen DeGeneres and director Todd Haynes – gathered on the Sony lot in Los Angeles to remember Heath Ledger on Saturday, PEOPLE has confirmed.

The gathering included industry luminaries and those connected to CAA (the agency that represented Ledger), including Cruise. It comes a week after relatives and close friends – including ex-girlfriend Naomi Watts – paid tribute to the 28-year-old actor at a smaller service at an L.A. cemetery.

Saturday's service began around noon on the lot, which is closed to the public. Attendees included Miller, Ledger's Casanova costar, and speakers included Haynes, who directed him in last year's Bob Dylan film I'm Not There.