Calabasas, Calif. • NBA legend Kobe Bryant, his daughter and seven others were killed Sunday when their helicopter plunged into a steep hillside in dense morning fog in Southern California, his sudden death at age 41 touching off an outpouring of grief for a star whose celebrity transcended basketball.

The chopper went down in Calabasas, about 30 miles northwest of downtown Los Angeles. Authorities said nine people were aboard and presumed dead. Bryant, an all-time basketball great who spent his entire 20-year career with the Los Angeles Lakers, was among the victims, a person familiar with the situation told The Associated Press.

Bryant’s 13-year-old daughter, Gianna, also was killed, a different person familiar with the case said.

Los Angeles County Sheriff Alex Villanueva would not confirm the identities of the victims Sunday pending official word from the coroner.

“God bless their souls,” Villanueva said at a news conference.

The cause of the crash was unknown.

News of the charismatic superstar’s death rocketed around the sports and entertainment worlds, with many taking to Twitter to register their shock, disbelief and anguish.

“Words can’t describe the pain I am feeling. I loved Kobe — he was like a little brother to me,” retired NBA great Michael Jordan said. “We used to talk often, and I will miss those conversations very much. He was a fierce competitor, one of the greats of the game and a creative force.”

NBA players were in tears during pregame warm-ups as crowds chanted “Kobe! Kobe!” Tiger Woods was unaware of the news during his final round at Torrey Pines in San Diego when he started hearing the gallery yell “Do it for Mamba,” referring to Bryant by his nickname.

The medical examiner’s office said specialists were working at the scene to recover the bodies, and investigators were trying to confirm identities. Federal transportation safety investigators were en route.

Bryant’s helicopter left Santa Ana shortly after 9 a.m. and circled for a time just east of Interstate 5, near Glendale. Air traffic controllers noted poor visibility around Burbank, just to the north, and Van Nuys, to the northwest.

After holding up the helicopter for other aircraft, they cleared the Sikorsky S-76 to proceed north along Interstate 5 through Burbank before turning west to follow U.S Route 101, the Ventura Highway.

Shortly after 9:40 a.m., the helicopter turned again, toward the southeast, and climbed to more than 2,000 feet above sea level. It then descended and crashed into the hillside at about 1,400 feet, according to data from Flightradar24.

When it struck the ground, the helicopter was flying at about 160 knots (184 mph) and descending at a rate of more than 4,000 feet per minute, the Flightradar24 data showed.

At the time of the crash, the Los Angles County Sheriff’s Department had grounded its own helicopters because of the poor weather conditions. The impact scattered debris over an area about the size of a football field, Villanueva said.

Among other things, investigators will look at the pilot’s history, the chopper’s maintenance history, and the records of its owner and operator, NTSB board member Jennifer Homendy said at a news conference.

Justin Green, an aviation attorney in New York who flew helicopters in the Marine Corps, said weather may have contributed to the crash. Pilots can become disoriented in low visibility, losing track of which direction is up. Green said a pilot flying an S-76 would be instrument-rated, meaning they could fly the helicopter without relying on visual cues from outside.

All around the world, people were glued to their phones and TV screens as news of the crash spread and networks broke into programming with live coverage. A visibly shaken LeBron James wiped his eyes with tissues and walked away alone from the Lakers plane that had just landed in Southern California.

Thousands of people gathered to mourn Bryant outside the Staples Center in downtown Los Angeles. Mourners in No. 24 jerseys mixed with those in fancy dress arriving at the downtown arena for Sunday evening’s Grammy Awards.

People carried flowers and chanted “Kobe!” and “MVP!” under giant video screens showing Bryant’s smiling face.

“This is where we needed to be,” said Naveen Cheerath, 31.

Bryant retired in 2016 as the third-leading scorer in NBA history, finishing two decades with the Lakers as a prolific shot-maker with a sublime all-around game and a relentless competitive ethic. He held that spot in the league scoring ranks until Saturday night, when the Lakers’ James passed him for third place during a game in Philadelphia, Bryant’s hometown.

“Continuing to move the game forward (at)KingJames,” Bryant wrote in his last tweet. “Much respect my brother.”

Bryant had one of the greatest careers in recent NBA history and became one of the game’s most popular players as the face of the 16-time NBA champion Lakers franchise. He was the league MVP in 2008 and a two-time NBA scoring champion, and he earned 12 selections to the NBA’s All-Defensive teams.

He teamed with O’Neal in a combustible partnership to lead the Lakers to consecutive NBA titles in 2000, 2001 and 2002.

His Lakers tenure was marred by scandal, when in 2003, Bryant was accused of raping a 19-year-old employee at a Colorado resort. He said the two had consensual sex, and prosecutors later dropped the felony sexual assault charge at the request of the accuser. The woman later filed a civil suit against Bryant that was settled out of court.

Bryant went on to win two more titles in 2009 and 2010, and retired in 2016 after scoring 60 points in his final NBA game.

After leaving the game, Bryant had more time to play coach to daughter Gianna, who had a budding basketball career of her own and, her father said, wanted to one day play in the WNBA. They were seen sitting courtside at a Brooklyn Nets game late last year, Bryant clearly passing along his wisdom to his daughter. He regularly showcased her talents on the court on social media.

Bryant’s death was felt particularly painfully in Los Angeles, where he was unquestionably the most popular athlete and one of the city’s most beloved public figures. Hundreds of fans — many in Bryant jerseys and Lakers gear — spontaneously gathered at Staples Center and in the surrounding LA Live entertainment complex, weeping and staring at video boards with Bryant’s image.

Among those killed were John Altobelli, head coach of Southern California’s Orange Coast College baseball team, his wife, Keri, and daughter, Alyssa, who played on the same team as Bryant’s daughter, said his brother, Tony, who is the sports information director at the school.

The National Transportation Safety Board typically issues a preliminary report within about 10 days that will give a rough summary of what investigators have learned. A ruling on the cause can take a year or more.

Colin Storm was in his living room in Calabasas when he heard what sounded to him like a low-flying airplane or helicopter.

“It was very foggy so we couldn’t see anything,” he said. “But then we heard some sputtering and then a boom.”

The fog cleared a bit, and Storm could see smoke rising from the hillside in front of his home.

Firefighters hiked in with medical equipment and hoses, and medical personnel rappelled to the site from a helicopter, but found no survivors, Los Angeles County Fire Chief Daryl Osby said.

Associated Press writers Christopher Weber in Los Angeles, David Koenig in Dallas, Mark J. Terrill and John Antczak in Calabasas, Tim Reynolds in Miami and Michael Rubinkam in northeastern Pennsylvania contributed to this report.