I first heard of this last week over facebook. Gigi confirmed it through a friend of hers that studies under Sifu Eng. There has been no formal announcement on his website yet as he passed last week.

Our deepest condolences to his family and friends. Being from the S.F. Bay Area, I remember Sifu Eng from back in the day when I first started Kung Fu. I never really interacted with him much but he has been a pillar of the Kung Fu community in the Silicon Valley.