So heartbreaking. English rocker Eric Clapton lived through the pain that no parent should ever have to endure: the loss of a child. Just days ahead of his biography Slowhand: The Life and Music of Eric Clapton, his biographer Philip Norman is sharing the harrowing details about the day that Eric’s four-year-old son Conor fell from a 53-floor high rise apartment window to his death in a tragic accident that inspired one of Eric’s most iconic songs, “Tears In Heaven.”

Eric shared Conor with his former mistress, Italian actress Lory del Santo but he had not been a big part of Conor’s early life, according to the Daily Mail. In March 1992, when Conor was four years old, Eric decided to take Conor for their first father-son outing together to the circus at Nassau Coliseum in Long Island. So he picked Conor up from Lory’s apartment on the 53rd floor of a high rise apartment building in NYC.

Eric Clapton Son Funeral
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Italian actress Lori del Santo and former partner, musician Eric Clapton attend the funeral of their son, four-and-a-half year-old Conor. | Location: Ripley, England, UK. (Photo by Georges DeKeerle/Sygma via Getty Images)

When Eric and Conor returned from their trip to the circus, Eric told Lory that he wanted to be a part of Conor’s life and he made plans to pick the toddler up again the next day for a trip to the Bronx Zoo and lunch at an Italian restaurant.

But the next morning, a janitor had arrived at Lory’s apartment to clean her windows as Conor and Lory waited for Eric to arrive. Conor was in the care of a nanny while Lory was in the bathroom, and the janitor asked the nanny to watch Conor as he left one of the windows open.

Eric Clapton Son Funeral
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Italian actress Lori del Santo and former partner, musician Eric Clapton attend the funeral of their son, four-and-a-half year-old Conor. | Location: Ripley, United Kingdom. (Photo by Georges DeKeerle/Sygma via Getty Images)

But Conor ran past the nanny and jumped up on the ledge where he would usually press his nose up against the window — but since the window was open, Conor fell over the ledge and disappeared. Lory called Eric to tell him that Conor was dead, but Eric didn’t believe it.

“Whatever physical damage Conor suffered in the fall, by the time I saw him they had restored his body to some normality,”  the 73-year-old recalled. “I remember looking at his beautiful face in repose and thinking, ‘This isn’t my son. It looks a bit like him, but he’s gone.'”