Cattrall, 61, confirmed on Sunday that her 55-year-old brother Chris had been found dead — just hours after asking fans to help find him after he went missing in Canada.
Parker, 52, commented on her former Sex and the City costar’s Instagram post, writing: “Dearest Kim, my love and condolences to you and yours and Godspeed to your beloved brother. Xx.”
Another one of Cattrall’s SATC costars, Cynthia Nixon, 51, also commented on the post, writing: “Hey Kim such awful news. So sorry to hear. Sending you love. XO.”
Later, Cattrall tweeted her thanks to her colleagues.
In her post announcing the tragic news, Cattrall thanked fans for their support and asked for privacy during the trying time.
“It is with great sadness that myself and my family announce the unexpected passing of our son and brother, Chris Cattrall,” she captioned a photo of the siblings. “At this time we ask for privacy. We want to thank you all on social media for your outpouring of love and support in this trying time.”
Canadian police are still investigating the circumstances surrounding Chris’ death. Royal Canadian Mounted Police Corporal Chris Warren told PEOPLE this week that Chris was found on his property Sunday and the “preliminary investigation suggests that there is no foul play suspected.”
The supportive messages from Cattrall’s former costars come in the wake of some recent bad blood over the actress’ decision not to return for a third SATC movie. Parker addressed the drama on Watch What Happens Live with Andy Cohen last week.
“What ties us together is this singular experience,” she said. “It was a professional experience but it became personal because it was years and years of our lives. I’m hoping that that sort of eclipses anything that’s been recently spoken — that that lingers. That many years spent doing something, that people had a connection with it is such a privilege.”