Those killed include two Napa residents, 50-year-old Daryl Horn and his 14-year-old son Joseph, and two from Bainbridge Island in Washington, 52-year-old Troy Biddle and his 13-year-old son Baden.
Watch the video above for more about the tragedy that happened over the holiday weekend.
Click here for the full story from reporter Dion Lim on a community in mourning following the tragic accident.