Katharine McPhee and David Foster have spoken out after the death of their son's nanny.

While speaking to Entertainment Tonight, the couple addressed the sudden death of Yadira Calito, the nanny to their two-year-old son Rennie.

"It's been tough for her," David, 73, said of his wife during the joint interview. "Yeah, it's been tough. She's managing."

"Yeah," Katharine, 39, added. "Thank you."

Yadira passed away at the age of 55 last month after being struck by a car at a Toyota dealership in the San Fernando Valley, California. She sustained fatal injuries and was pronounced dead in hospital.

Following the accident, the police shared a press release stating that an unnamed woman in her 50s died after a 2017 Toyota RAV4 collided with several people inside the dealership building.

According to the press release, the driver of the car was an 84-year-old woman from California. She was not hurt in the accident.

After the incident, Katharine left her and David's Hitman Tour early to tend to the family emergency.

"It's with heavy heart I announce I have to miss our final 2 shows of our Asia run," the singer and actress wrote on Instagram at the time. "David and I have had a horrible tragedy in our family and at least one of us needs to get back home to our family."

According to Yadira's online obituary, she is survived by her fiancé, four children and eight grandchildren.