The death of a Canadian woman whose body was discovered in a downtown Los Angeles hotel's rooftop water tank was the result of an accidental drowning, the city's coroner has ruled. 

Coroner's Lt. Fred Corral says 21-year-old Elisa Lam's cause of death was ruled an accident on Thursday. Corral says the body had no sign of trauma indicating foul play, but noted Lam had bipolar disorder.

Lam travelled alone to Los Angeles from Vancouver on Jan. 26 and was last seen five days later by workers at the historic Cecil Hotel near Skid Row.

Before she died, hotel surveillance footage showed Lam inside an elevator pushing buttons and sticking her head out the doors, looking in both directions.

Lam's body was found on Feb. 19 in the water tank after hotel guests complained of low water pressure.