The mother of Hector 'Macho' Camacho says the shot former world champion boxer will be taken off life support today, after three more of his sons arrive in Puerto Rico to be with him.
Maria Matias said she made the decision to have doctors remove him from life support, but the 50-year-old boxer's oldest son says he opposes that.
Ms Matias said three more of the boxer's sons would arrive in Puerto Rico to see him for the last time.
She said her son "died three days ago and he's only alive now because of a machine". Doctors say the fighter is clinically brain dead.
Camacho was shot in the face on Tuesday night in his home town of Bayamon as he and a friend sat in a Ford Mustang parked outside a bar.
Police spokesman Alex Diaz said officers found nine small bags of cocaine in the friend's pocket, and a 10th bag open inside the car.
Camacho's friend, identified as 49-year-old Adrian Mojica Moreno, was killed in the attack.
Doctors had initially said Camacho was expected to survive, but his condition worsened and his heart stopped briefly overnight on Tuesday.
Camacho was born in Bayamon, a city within the San Juan metropolitan area, but he grew up mostly in New York's Harlem neighbourhood, earning the nickname "the Harlem Heckler".
He won super lightweight, lightweight and junior welterweight world titles in the 1980s and fought high-profile bouts against Felix Trinidad, Julio Cesar Chavez and Sugar Ray Leonard.
Camacho knocked out Leonard in 1997, ending the former champ's final comeback attempt.
In recent years he divided his time between Puerto Rico and Florida, appearing regularly on Spanish-language television as well as on a reality show called 'Es Macho Time!' on YouTube.
In San Juan, he had been living in the beach community of Isla Verde, where he would readily pose for photos with tourists who recognised him on the street.
Camacho battled drugs, alcohol and other problems throughout his life. He was sentenced in 2007 to seven years in prison for burgling a computer store in Mississippi. While arresting him on the burglary charge in January 2005, police also found the drug ecstasy.
A judge eventually suspended all but one year of the sentence and gave Camacho probation, but he ended up serving two weeks in jail for breaking the probation order.
His wife also filed domestic abuse complaints against him twice before their divorce several years ago.
Camacho's eldest son, Hector Jr, said he wanted to keep his father alive.
"He's going to fight until the end. My father is a boxer," he said.
Lamenting the violence that grips Puerto Rico, a US island territory of nearly four million people that reported a record 1,117 homicides last year, Hector Jr said: "Death, jail, drugs, killings. That's what the streets are now."
Police have made no arrests over Camacho's shooting and said investigators continue to interview potential witnesses.
Captain Rafael Rosa said police were following several leads, but very few witnesses were co-operating. He would not say whether police had identified any suspects.
As some relatives and friends continued to pray for a miracle, condolences kept coming in for Camacho's family and preparations began for memorials and a funeral Mass.
Governor Luis Fortuno said: "'Macho' will always be remembered for his spontaneity and charisma in and out of the ring."
Also offering condolences was governor-elect Alejandro Garcia Padilla, who defeated Mr Fortuno in November.
"The life of Macho Camacho, like other great athletes of ours, united the country," he said. "We celebrated his triumphs in the streets and we applauded him with noble sportsmanship when he didn't prevail."