The Office of Chief Medical Examiner of the City of New York spokesperson told E! News in a statement, "The medical examiner's office is investigating the death of a man believed to be Dennis Shields, found at the Trump Tower. The investigation is ongoing, and we will release cause and manner of death when completed."
According to the New York Post and TMZ, Shields had suffered an apparent overdose. The outlets reported that his assistant had administered Narcan, used to reverse opioid overdoses, but was unable to revive him.
A New York Police Department spokesperson told People that "preliminarily," they are investigating the death "as a possible overdose."
Frankel is "heartbroken" about Shields' death, a source told E! News, adding, "This is really bad. It's dreadful. She's known him for over 20 years. She's heartbroken."
Her former Real Housewives co-star Carole Radziwill tweeted, "I just heard the sad news about Dennis. He was a good man. My condolences to all his family and friends. So tragic."