Just before air traffic controllers lost track of the helicopter that was carrying nine people, including Kobe Bryant, on Sunday, the pilot who was at the controls said that he was trying to fly higher to avoid a cloud layer, federal investigators said Monday.
The National Transportation Safety Board said there was no response from the pilot after controllers asked for more information, and radar suggested that the helicopter ascended to 2,300 feet and began a descending turn to the left.
Although investigators are scrutinizing weather conditions at the time of the crash — part of Southern California was shrouded in fog on Sunday morning — they are also examining the possibility that other issues played a role in the crash.
“We take a broad look at everything around an investigation, around an accident,” Jennifer Homendy, a member of the N.T.S.B., said at a news conference in California on Monday afternoon. “We look at man, machine and the environment, and weather is just a small portion of that.”
The helicopter did not carry a cockpit voice recorder, and investigators are spending their days searching a debris field of about 500 to 600 feet, trying to recover perishable evidence. Federal officials are not expected to reach a conclusion about the cause of the accident for months.
But asked Monday whether the crash had been survivable, Homendy replied: “It was a pretty devastating accident.”
The Lakers and the Clippers will not play as planned on Tuesday night, the N.B.A. said Monday, as the players and others throughout basketball grieve the death of Bryant, a star with the Lakers for two decades.
In a statement, the league said the game had been postponed to a later date, which was not immediately announced, “out of respect for the Lakers organization.”
Soon after the league’s announcement, the Lakers expressed gratitude for the public outpouring of support.
“This is a very difficult time for all of us,” the team said in a statement.
The Lakers last played Saturday, when they lost at Philadelphia, and were traveling back to California when word of the helicopter crash that took Bryant’s life emerged. Staples Center, where both the Lakers and Clippers play their home games, has been the site of impromptu gatherings and tributes since Bryant’s death.
Eight other N.B.A. games scheduled for Tuesday are expected to be played as planned.
On Monday night, LeBron James posted a tribute to Kobe Bryant and his daughter Gianna on Instagram, saying he was “heartbroken and devastated.” He referred to Bryant as his brother.
“Man I sitting here trying to write something for this post but every time I try I begin crying again just thinking about you, niece Gigi and the friendship/bond/brotherhood we had!”
James wrote. “I literally just heard your voice Sunday morning before I left Philly to head back to LA. Didn’t think for one bit in a million years that would be the last conversation we’d have.” He added, “My heart goes to Vanessa and the kids. I promise you I’ll continue your legacy man!”
On Sunday, footage emerged of James and other Lakers teammates coming off the team plane and embracing one another. Bryant’s death came the day after James passed him on the N.B.A.’s all-time scoring list.
When the helicopter carrying Bryant departed from Orange County on Sunday morning, visibility had been fine.
But less than an hour later, as the aircraft circled over Griffith Park in Los Angeles awaiting clearance from air traffic controllers, it was mired in a thick fog. Drivers on the freeway could barely see the hillsides. The Los Angeles Police Department had grounded its fleet of helicopters.
Kobe Bryant, Gianna Bryant, Payton Chester, Sarah Chester, Ara Zobayan, Alyssa Altobelli, Keri Altobelli, John Altobelli, Christina Mauser,