LOS ANGELES — An autopsy on a Canadian tourist’s body failed to determine whether she was killed or died accidentally in a giant water cistern on a downtown Los Angeles hotel roof.

The results were inconclusive, so coroner’s officials said Thursday that they will have to wait for toxicological tests to determine a cause of death for Elisa Lam, 21, of Vancouver, British Columbia.

Lam’s body was found Tuesday in one of several water cisterns on top of the 600-room hotel near Skid Row.

The hotel will sanitize the water lines and retest them before they are put back into operation, a county official said.

Lam traveled alone to Los Angeles on Jan. 26 and was last seen five days later by hotel workers. She intended to travel to Santa Cruz.