LOS ANGELES -

 Investigators were trying to determine today how the  body of a 21-year-old tourist from Canada who had been missing for weeks  ended up inside a water tank atop a downtown Los Angeles hotel where she had  been staying.
      Tourist Elisa Lam of Vancouver, British Columbia, had been missing since  Jan. 31, when she stopped making daily contact with her parents, according to  Los Angeles police.
      Lam, who arrived in Los Angeles on Jan. 26, had been traveling alone and  was staying at the Cecil Hotel at 640 Main St., police said. Surveillance  video from a hotel elevator showed her pressing all of the elevator's buttons  and stepping in and out of the car.
      Her final U.S. destination was to have been Santa Cruz, police said.
      Her whereabouts remained a mystery until around 10:15 a.m. Tuesday, when  a maintenance worker went to the rooftop tanks -- which hold water for human  use -- after guests complained of low water pressure. The worker found the body  inside a tank.
      Firefighters used cutting tools to gain access to the body and remove it.
      Public health officials reassured hotel guests Tuesday that the water in  the building was not going to make them sick.
      Hotel officials said the rooftop access doors were locked and had  alarms, but the four water storage tanks atop the building were not locked,  police said.
      "Body markings" on the corpse match those on Lam, Diana Figueroa of  the Los Angeles Police Department's Media Relations Section said late Tuesday.
      A coroner's lieutenant said the woman had been identified, but his  office would not release the name because next of kin had yet to be notified.
      The roof had been searched after Lam was reported missing, but it was  unclear if the tanks were checked, Los Angeles police Sgt. Rudy Lopez said.
      The hotel, which offers rooms for less than $50 per night, closed for  business on Tuesday and will remain shut for at least a few days, according to  someone answering the phone this morning.