Dean Martin 'never fully recovered' from son's death in military training flight.

After losing his "golden boy," Dean Martin, known as the "King of Cool," never fully recovered.

In 1985, the '50s crooner and Rat Pack member experienced tragedy when he lost his oldest son, Dean Paul Martin, in a military jet crash during a routine exercise in 1987. At the time of his death, Dean was 35 years old.

"William Keck, author, stated to Planet Chronicle Digital that Dean Martin's final years were extremely sad following the loss of his son. It was as if he was a candle without a flame."

A former National Enquirer reporter, Keck, has penned a new memoir titled "When You Step Upon a Star: Cringeworthy Confessions of a Tabloid Bad Boy," where he reveals the celebrities he befriended, protected, and wronged.

Keck, who covered Martin's final years, stated that he felt a strong urge to safeguard the singer.

"Keck stated that the man he met in person was still as kind as he appeared on TV. He would always greet Keck and say he'd return to the stage one day. However, Keck realized that the man's days were over."

"Keck remembered how he would eat alone, wearing the same navy pants and light blue shirt every time. He would order the same dish, clams casino, and let the clam juice drip down his shirt. Nearby, his ex-wife Jeanne would be observed, making it a strange sight to see a barely moving wax figure."

Keck wrote in his book that Martin, who had lost his son, was suffering from a broken heart. Every evening, he would go to La Famiglia, an Italian restaurant in Beverly Hills, where the same dish awaited him. He was always seen quietly twirling his pasta as he sat alone.

Keck was always greeted with a smile from Martin whenever he saw the young writer. Martin also permitted Keck to capture photos of him for his narratives.

"Keck explained that the issue was that the photo always appeared the same because he consistently wore the same outfit, making it difficult to determine whether it was taken six months or a year ago."

Keck spoke to many friends to understand Martin's life outside the public eye. It was evident that the patriarch was going through pain.

Dean Paul, known as "Dino Jr.," was a multitalented individual who gained recognition for his skills in tennis and his rock band with friends Desi Arnaz Jr. and Billy Hinsche. Eventually, he followed in his father's footsteps and pursued acting, earning a Golden Globe nomination for his role in the 1979 film "Players."

In 1981, Dean Paul found his calling as a pilot with the Air National Guard, after being a semi-professional football player, race car driver, and pre-med student.

"Martin expressed pride in him, stating, "I'd be proud even if he didn't become a jet pilot because he's a good boy. He just doesn't know what he wants to be.""

The New York Times reported that Dean Paul and Capt. Ramon Ortiz, 39, were among the three F4-C Phantom jets conducting maneuvers near the San Bernadino Mountain range. The plane disappeared and their remains were discovered six days later.

At the time of impact, Capt. Dean Paul Martin and Capt. Ramon Ortiz tragically lost their lives, as stated by Sgt. Carolyn Hamilton, an Air National Guard spokeswoman.

Officials reported that the jet flown by Dean Paul descended almost 4,000 feet from its last radar altitude reading of 9,300 feet. The outlet stated that it struck the mountain side at approximately 400 miles per hour.

"Dean Martin was deeply affected by the death of Dean Paul, as stated by Keck. Everyone who knew Dean Martin would confirm this impact, and it was his close friend Rich Little who revealed that the loss of his son marked the end of Dean Martin, leaving a lasting impact on him that never fully recovered."

According to the Associated Press, singer Paul Anka stated that the death of Martin's son marked a significant turning point.

"Anka stated, "After that event in his life, things really changed. He told me, 'I’m just waiting to die. Just waiting to die.'""

On Christmas Day 1995, Martin died at his Beverly Hills residence at the age of 78.

"Keck remarked, "In a way, he deceived us. He persisted. We had planned to attend his funeral, which was a private VIP service with numerous celebrities. Everyone wanted to pay their respects. At one point, it became dark, and all you could hear was Rosemary Clooney, George Clooney's aunt, singing 'Everybody Loves Somebody'.""

""In the end, it was a friend honoring him," Keck acknowledged, describing the surreal experience."

Martin's greetings at the restaurant are a source of bittersweet memories for Keck.

"Keck recounted how he would always be greeted by the warm smile of the person he remembered, but it was heartbreaking to think that his broken heart never healed."

The Associated Press contributed to this report.