TORONTO -- A third resident of an Ontario facility that supports adults with developmental and physical disabilities has died after a major COVID-19 outbreak.

Nearly all the residents at Participation House, located next to Markham Stouffville Hospital in Markham, have contracted the novel coronavirus.

On Thursday, Markham Mayor Frank Scarpitti said he was "'deeply saddened"' to report the death of a 70-year-old resident, who passed away in hospital.

"With a heavy heart I offer my deepest condolences to the family of a 70-year-old man who passed away at Markham Stouffville Hospital," Scarpitti said. "We are deeply saddened, our thoughts are with everyone affected by this heartbreaking loss."

With a heavy heart I offer my deepest condolences to the family of a 70 year old man who passed away at Markham Stouffville Hospital. He was a resident of Participation House. We are deeply saddened, our thoughts are with everyone affected but this heartbreaking loss. #COVID19 — Mayor Frank Scarpitti (@frankscarpitti) April 23, 2020

The first death of a resident at the facility was confirmed by Markham Stouffville Hospital in a statement earlier this month, sent on behalf of the family.

According to the family, 58-year-old Martin Frogley, died after contracting COVID-19 at the facility.

"He passed peacefully listening to music he loved. He was a wonderful son, uncle and the best brother anyone could ever ask for," the family said. "Thanks to all staff at the Participation House for their exceptional care and to the staff at Markham Stouffville Hospital for making things comfortable for him on his last days."

The second death at the facility was confirmed by the brother of the victim on April 15.

Earl Baird told CTV News Toronto that his sister Patricia "Patty" Baird tested positive for the virus on April 13. He said the 53-year-old lived at Participation House for five years.

"We all know of this dreadful virus and now our family has been personally affected," he wrote in a Facebook post. I cannot describe the pure love and a heart that our universe could not contain that was within Patty.

Participation House has been plagued with a staffing shortage ever since the outbreak of the novel coronavirus was declared at the facility earlier this month.

Markham Stouffville Hospital said they assembled a “rapid response team” to support Participation House, including patient care and HR support to help with staffing needs. They are also providing meals for residents as well as personal protective equipment.