A desk clerk and café hostess at the hotel said they remember seeing Lam, but didn't remember seeing her with anyone. The last people known to have seen Lam are hotel staff.
"The water tank above has a separate latch, or hatch, on top of it that is not secured by any lock. Anybody could open it, but the roof is secured with an alarm and a lock and a key to the door access," said LAPD Sgt. Rudy Lopez.
Officials say that water tank, along with two others, supplies water to the hotel guests' rooms.
Fire officials say they were told by city health inspectors that the water in the tank contains no biohazards, but they turned the water supply off to the rooms and the rest of the hotel immediately after the discovery of the body.
It's unclear how the body ended up in the water tank. Authorities are not yet calling the case a murder investigation, just a suspicious death case.