TIM Russert’s widow says he had been under an extraordinary amount of stress in the days before his death.

Putting his widowed father, Tim Sr., 84, into an assisted living facility was “a huge psychological strain for him,” writer Maureen Orth told People magazine yesterday.

Also, a three-day trip to Europe with her and son Luke was taxing.

“It was very hot and humid in Rome,” she said. “I was so tired. I told him: ‘I don’t know how you do it.’ ”