What happened to 27-year-old aspiring model Adrienne Martin that led to her being found dead earlier this week at August Busch IV's mansion? Investigators are reportedly saying it could take over a month to determine the cause of death, but ET has obtained the 911 call from that tragic night.

August Busch IV, 46, is the heir to Anheuser-Busch dynasty, and it was his $2 million mansion in the Huntleigh, Mo. where Martin was found dead. In the 911 call, a man tells the dispatcher, "This girl is just not waking up. We can't get her to..." When asked if Martin was still breathing, the man replied, "We don't know."

The call was made to Frontenac Police Department on Dec. 19 around 1:12 p.m. According to police, the man who called 911 was Michael Jung, a home staff employee of August Busch IV, but Busch was in the house at the time.

The investigation is continuing by the St. Louis County Medical Examiner and the police department as to cause of death. Chief Thomas Becker told ET of the investigation, "There is no concern for the general public safety in this case, and we will proceed with our investigation carefully and professionally."

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