'The Real Housewives of New York City' stars Sonja Morgan and Carole Radziwill have expressed their condolences in the wake of the devastating news about Bethenny's on-/off-boyfriend.

• Aug 11, 2018

AceShowbiz - Bethenny Frankel is grieving over the sudden death of her on-/off-boyfriend Dennis Shields. "She's heartbroken," a source supposedly close to the reality TV star tells E! News. "This is really bad. It's dreadful. She's known him for over 20 years."

Bethenny had known Dennis for almost 30 years, but they only began dating in 2016, three years after she split and filed for divorce from Jason Hoppy. "They had a 27-year friendship before they dated so they picked that up where they left off once they realized they didn't work as a couple," a source told PEOPLE after Bethenny and Dennis split. "Her daughter adores him and his family, and she comes first above all."

Following the sad news, some of Bethenny's "The Real Housewives of New York City" co-stars have publicly shown their support for her. Bethenny's best friend Sonja Morgan said to Radar Online, "Dennis was important to her, and her daughter. Another tragedy in her life. I'm so sad for her." Sonja added that she had flown to Costa Rica for vacation before she heard the news of Dennis' passing, so she won't be able to attend Dennis' services.

Meanwhile, Bethenny's frenemy Carole Radziwill wrote on Twitter, "I just heard the sad news about Dennis. He was a good man. My condolences to all his family and friends. So tragic."

I just heard the sad news about Dennis. He was a good man. My condolences to all his family and friends. So tragic.

— Carole Radziwill (@CaroleRadziwill) August 10, 2018

Dennis was found unresponsive at his Trump Tower apartment in New York City on Friday morning, August 10. The 51-year-old had allegedly asked his assistant to administer Narcan, a drug used as emergency treatment to counter the affects of an opiod overdose, but he lost consciousness before the medication kicked in. Paramedics arrived to the building but failed to revive him and pronounced dead.

The medical examiner's office is currently investigating his death, which is suspected as a possible overdose.

Dennis' estranged wife Jill Shields said in statement regarding her husband's sudden passing, "Dennis' family is devastated by this terrible news. He was a loving father and friend. We ask that the media respect our privacy during this time of loss."