The former Great British Bake Off judge had viewers in tears as she relived the day her 19-year-old son died in a car crash.
The Mary Berry Story returned for part two on Friday night and the treasured TV presenter shared a tragic story about her son William, who died in 1989 when he was just 19 years old.
Berry recalled how William had returned home from university and borrowed the car when he was involved in an accident.
She said: "Will came back from university on the Friday night and he hadn't been home for a few weekends, so I thought I'll do roast lamb, because it's his favourite."
"I can remember Will walking through the door on that Friday and asking 'Mum, who's coming?' And I said, 'It's you, it's so lovely to have you home and Annabel and Tom too', so we had a lovely family meal."
The former Great British Bake Off host then went on to describe the events of the next day, during which William went for a drive in his parents' car, but was involved in a crash which then took his life.
"It was a glorious January day," Mary reflected. "And it was sort of one o'clock and he wasn't home."
Choking back tears, she added: "The doorbell rang and there was a policeman there and immediately then I knew why. And he said there's been an accident and I'm sorry to say your son is dead."
The day after the tragic accident, Mary and her family went to church where she spotted a memorial plaque created by a fellow mum who had lost three sons during World War One.
"I looked and I thought, I knew how I was feeling having lost one, how would she be feeling having lost three? Then I thought, well we're just so lucky to still have our other two children.
"We had William for 19 years and he was just such fun and we have great, great memories."
Mary Berry has two children, Annabel and Thomas Hunnings with husband Paul. She added how grateful she was to have the support of her husband, saying: "It was a great comfort to us both to have each other. Your life long partner. I was so lucky to have him."
The Mary Berry Story is available to watch on BBC iPlayer.
