Jack Osbourne fought back tears as he recalled the exact moment he learned his father, Ozzy Osbourne, died.

In a YouTube video posted Wednesday, Jack shared that a person who worked for his family for 30 years knocked on his door at his home in Los Angeles at 3:45 in the morning and told him the sad news.

“When I looked through my window and I saw it was him, I knew something bad had happened,” Jack said.

“‘I was informed that my father had passed,” he continued.

Jack shared that he was able to spend extra time with Ozzy during the rock icon’s last days after he stayed in the UK following Ozzy’s final show with Black Sabbath in Birmingham on July 5. Jack said he and his family were planning to go to Portugal for vacation but canceled and stayed in England for another week after his kids all got the stomach flu.

“I’ve never been more grateful for my kids to have the stomach flu than I am today,” he reflected.

Jack noted that while he was sad over his father’s death, he was at peace knowing he was no longer in pain and suffering due to his declining health.

“I wish he was still here, I wish he was, you know, still with us all, but, he was having a rough go and I think people saw that at the show,” he said. “But nobody expected it to happen as quickly as it did and when it did.”

“It was not anything that was on our radar,” he added.

Jack said his father was looking forward to a new phase in life after his final show, and wanted to spend more time in England as well as be with his grandchildren.

The former reality star, 39, tearfully let listeners know how grateful he was to have Ozzy as a father.

“He was deeply complicated,” he shared. “He was funny, and weird and awkward and clumsy and just hilarious and so insightful.”

Jack also stressed that Ozzy “knew what was going on all the time,” despite appearances.

“People may have thought he was checked out, but most of the time he wanted you to think he was checked out,” he said. “But he was very aware, always.”

Ozzy died on July 22 of a heart attack. He also suffered from coronary artery disease and Parkinson’s disease. He was 76.

A source told Page Six that Ozzy was “re-energized” by his final Black Sabbath concert that took place just two weeks before he died.

“It energized him — it filled him with life,” a longtime pal told us. “He’d really been slowing down, and then after the show he was really back to be being himself. It’s a beautiful ending.”