Everybody wanders about their future method of dying. Fire has got to the worst.
.
Strong chance that those that died were on the upper floor, and were choked to death by toxic gas rising from a fire below.
Freebasing with butane is common in Oakland, and would be the most likely source of fire.
The butane fills the room, and if it ignites it flashes across the entire room. Everything ignites quickly.
.