Austrian police say an autopsy has not revealed the cause of death of a 25-year old woman from Colorado whose body was found in her Vienna apartment.

Police spokesman Thomas Keiblinger said Thursday that investigators are now awaiting the results of toxicological tests over the next few days.

U.S. authorities have identified her as Lauren Mann.

Police and firefighters who forced open her door Tuesday evening found the half-naked body on a mattress in the bedroom. Mann had been working as an au pair, and police were alerted by Mann’s employer after she did not show up for work.

Mann graduated in 2012 from the University of Colorado-Boulder’s College of Music.