Kobe Bryant's unexpected death leaves the world grieving, searching for answers

The federal probe into the devastating helicopter crash that killed retired NBA star Kobe Bryant, his 13-year-old daughter and seven others has investigators exploring why the pilot took flight in weather so foggy it had prompted local law enforcement agencies to ground its choppers.

An 18-member team from the National Transportation Safety Board, along with help from the FBI, continued on Monday to comb through the wreckage of the 1991 Sikorsky S-76 aircraft that slammed into a hillside on Sunday morning in Calabasas, California, killing everyone onboard and sending shockwaves across the globe.

Bryant, 41, and his 13-year-old daughter Gianna "Gigi" Bryant were among those who were instantly killed after the helicopter faded from radar just before 10 a.m. local time on Sunday. Reports of the crash into the steep hillside followed soon after.

The helicopter pilot, identified Monday as Ara Zobayan by Los Angeles aviation company Group 3 Aviation, the company that trained him, had climbed to more than 2,000 feet when the aircraft made an unusual and rapid descent just before it crashed, according to information from the aviation database Flightradar24.

Investigators had no immediate explanation for the aircraft's rapid descent.

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

"It was a pretty devastating accident scene," NTSB board member Jennifer Homendy said at a press conference Monday evening.

The listed owner of the aircraft is Island Express, but it is unclear if Bryant rented it or had a long-term arrangement with the company to use it. The helicopter was painted with Bryant's logo.

Eyewitness Scott Daehlin described the fog as "like jumping into a pool of milk."

Daehlin told ABC News that he was setting up audio equipment for Sunday service at the Church In The Canyon in Calabasas when he heard a big thud and what sounded like a fuselage breaking apart inside the canyon.

While Daehlin could hear the helicopter, it was impossible to see the crash because of the fog, he said. He then called 911 and told dispatchers that something horrible had happened.

Members of the FBI were sent to the crash site and are assisting the NTSB with collecting and documenting the evidence.

Jennifer Homendy, a member of the NTSB board, said investigators will look into the history of the pilot and maintenance records of the helicopter. It was not immediately clear if the helicopter was equipped with a black box.

The Los Angeles County Medical Examiner said that because of the difficult terrain at the crash site, it could take several days to complete the recovery.

The medical examiner's Special Operations Response Team recovered three bodies from the wreckage on Sunday before recovery operations were suspended due to darkness and safety concerns, the agency said in a statement. The team returned to the crash site on Monday and were working to recover the remaining victims, according to the statement.

The bodies are being taken to the medical examiner's Forensic Science Center for examination and formal identification.

The LA County Sheriff’s Department has asked the public to stay away, calling the scene a logistical nightmare. The sheriff said Monday people tried to access the site overnight and it was now being patrolled by horseback and ATV.

The Los Angeles Police Department said that Sunday's weather conditions did not meet its standards for flying -- an 800-foot cloud cieling and 2 miles of visibility -- at the time of the crash yesterday morning. The LAPD’s fleet was grounded at the time of the accident.

The pilot was flying under visual flight rules due to the foggy conditions and requested authorization to fly through transit-controlled airspace, according to the NTSB. After a 12-minute wait due to traffic, the authorization was approved. Four minutes later, the pilot told air traffic controllers he was flying higher to avoid a cloud layer. Traffic went silent, with no response from the pilot in response to the request, the NTSB said.

Other victims killed in the crash included John Altobelli, a local college baseball coach, as well as his wife, Kerri Altobelli, and his daughter, Alyssa Altobelli. Christina Mauser, an assistant girls basketball coach for a private school in Orange County, was also killed in the crash, her husband confirmed on Facebook.

Two other people aboard the doomed flight were identified as Sarah and Peyton Chester, ABC News has confirmed.

Bryant and the others who perished were flying from Orange County, where Bryant has a home in Newport Park, to the Mamba Sports Academy in Thousand Oaks, a sports facility where the former LA Lakers' star hosted basketball clinics. Bryant's daughter's basketball team was scheduled to play in the Mamba Cup, a youth basketball tournament that's named after Bryant's moniker.

The Lakers game against the Los Angeles Clippers scheduled for Tuesday night at the Staples Center has been postponed "out of respect for the Lakers organization, which is deeply grieving the tragic loss of Lakers legend Kobe Bryant, his daughter Gianna and seven other people in a helicopter crash on Sunday," the NBA said in a statement. The game will be rescheduled for a later date.

Meanwhile, tributes have been pouring in from all over the world. Bryant's image was splashed across newspapers Monday morning as basketball fans and beyond begin to mourn the loss of the hoops legend.

Shaquille O'Neal, Bryant's former LA Lakers teammate who won three consecutive NBA championships with him in 2000, 2001 and 2002, posted a picture of the two embracing, and said that "there are no words to express the pain I’m going through now with this tragic and sad moment."

Another close friend and retired basketball star Dwyane Wade paid an emotional tribute to Bryant on Instagram.

Basketball legend and principal owner of the Charlotte Hornets Michael Jordan issued a statement saying that Bryant "was like a little brother to me."

Bryant was drafted to the NBA out of high school in 1996 and spent his entire 20-year career with the Los Angeles Lakers, winning five NBA championships. He was awarded NBA MVP in 2008 and NBA Finals MVP in 2009 and 2010.

Bryant won gold medals as a member of the U.S. men's basketball team in the 2008 Summer Olympics in Beijing and the 2012 Summer Olympics in London.

Bryant's career was marred, however, during a 2005 trial when he was accused of sexual assault by an employee at a Vail, Colorado, hotel. Bryant always denied the encounter was nonconsensual and the case was later dismissed after the victim said she did not want to testify and the two parties settled a civil suit.

LeBron James surpassed Bryant on the all-time scoring list on Saturday during the Lakers' game against the Philadelphia 76ers.

"I'm happy just to be in any conversation with Kobe Bean Bryant -- one of the all-time greatest basketball players to ever play, one of the all-time greatest Lakers," James told reporters after the game. "The man got two jerseys hanging up in Staples Center. It's just crazy."

In 2018, Bryant won an Academy Award for his animated short "Dear Basketball," which is based on a poem he wrote in 2015 when he announced his retirement.

ABC News' Julia Jacobo, Joshua Hoyos and Tom Llamas contributed to this report.