Former UFC champion Conor McGregor was among the fighters and fans to send their condolences to the 37-year-old boxer and former mixed martial arts (MMA) star.

Former UFC heavyweight champion Francis Ngannou’s 15-month-old son Kobe has died, the boxer announced in a social media post on Monday.

“Too soon to leave but yet he’s gone. My little boy, my mate, my partner Kobe was full of life and joy. Now, he’s laying without life. I shouted his name over and over but he’s not responding,” Ngannou wrote on Instagram.

“I was my best self next to him and now I have no clue of who I am,” he added. “Life is so unfair to hit us where it hurts the most.

“How do you deal with such a thing? How can you live with it? Please help me if you have an idea because I really don’t know what to do and how to deal with this.”

The 37-year-old French Cameroonian fighter didn’t disclose the cause of his son’s death.

A few hours before revealing Kobe’s death, Ngannou had posted on X, without reference to his son: “What’s the purpose of life if what we’re fighting tooth and nail to get away from is what finally hit us the hardest?

“Why is life so unfair and merciless? Why does life always take what we don’t have? I’m f*cking tired.”

Many of Ngannou’s contemporaries offered their condolences to the fighter, including former UFC champion Conor McGregor who wrote on X: “I am so sorry to hear of your loss Francis, my prayers are with you and your family at this time.”

Ngannou’s manager Marquel Martin said he was “heartbroken” for the fighter. “I’m so sorry that you and your family are going through this,” Martin wrote on Instagram.

“I don’t have the words to even begin to tell you how bad I feel for you. I'm trying to write this without breaking down again. We’ve had our ups and downs as brothers, but NOTHING comes before our families and the love that we have for them.”

Veteran ring announcer Michael Buffer said on social media: “The entire world of sports and beyond stand crushed and painfully supportive with Francis at this time. Please know that millions of us embrace little Kobe with our prayers.”

Ngannou had made a living in the UFC, where he had been heavyweight champion, but the veteran fighter has recently switched to professional boxing.

In his first professional fight, dubbed the ‘Battle of the Baddest’, against Tyson Fury, Ngannou put on a good show with onlookers surprised by how quickly he adapted to life as a boxer and by how comfortable he looked against someone regarded as one of the best heavyweight boxers of the current generation in an eventual loss.

Ngannou was knocked out by Anthony Joshua in Saudi Arabia last month, his second heavyweight defeat since switching from MMA. After the fight, he dismissed the suggestion of returning permanently to MMA where he made his name.