Lynne Spalding, 57, disappeared from her room at San Francisco General Hospital on September 21. The mother-of-two, who had lived in the US for 23 years, was last seen in bed at 10.15am that day by a nurse.
She was found by a member of the hospital’s engineering staff on a routine check 17 days after she vanished.
Family spokesman David Perry said the coroner had not yet established a cause or time of death but investigators had ruled out foul play.
San Francisco mayor Ed Lee said an independent consultant would investigate the hospital’s security and patient safety protocols, the Associated Press reported.
“This should not have happened, we all agree,” Mr Lee said. “And we want to prevent it from ever happening again.”
There is a separate police inquiry into Ms Spalding’s death and an internal investigation of hospital security measures by San Francisco sheriff’s department.
“A thorough independent review is required, and we will do that,” Mr Lee said. “The city is responsible for what happened here.” Officials said they were investigating how she got on to the outside stairwell, what caused her death and why a search did not locate her sooner.
The hospital and sheriff’s department conducted a search of the premises and Ms Spalding’s friends and relatives spent days scouring the city’s streets with posters because they were “under the assumption that San Francisco General had been searched and Lynne was not here”.
“Lynne Spalding died alone, in the stairwell, at one of the finest medical institutions in this country,” said Mr Perry.
“I hear that the San Francisco sheriff’s department initiated a search. Well, evidently it wasn’t a very good one. I think there are a lot of questions to be asked.”