The charter flight left Paris on Monday morning, carrying Mayor Karen Bass, local Olympic organizers and a few dozen athletes home from the 2024 Summer Games.

About eight hours into the trip, somewhere over Wyoming, a small group of officials walked to the back of the plane with a bubble-wrapped package. Using scissors, they peeled away the protective coating to reveal an old, burnished-wood box.

2024 Paris Summer Olympic Games

Inside was the official Olympic flag, making its way to Los Angeles.

“It’s like a trigger,” Bass said later. “It triggers that now the clock is ticking.”

With four years to go until the 2028 Summer Games in L.A., there is much to do.

Scores of staff members from the LA28 organizing committee have been in France for weeks — and will remain through the Paralympics later this month — to get a behind-the-scenes look at how things were done.

Delta flight attendants display a briefcase that holds the Olympic flag. It features stickers from past Olympic host cities.

(David Wharton)

The first chore on their to-do list now involves pouring over hundreds of pages of notes taken while observing the fine details of venue management, ticketing, transportation and other aspects of the Games.

LA28 must continue negotiating with venues it wants to add to a roster that already includes SoFi Stadium, the Intuit Dome and Crypto.com Arena. Agreements must be finalized with the City of L.A. and neighboring municipalities — such as Long Beach, Santa Monica and Pasadena — that will host events.

Security is another issue, requiring coordination with federal and local authorities.

“In L.A. we have lots of incredibly big, global events,” said Casey Wasserman, chairman of the private organizing committee. “We are used to different security protocols for those events.”

Wasserman also came away from Paris with a big-picture lesson.

“They were willing to do things differently and take chances,” he said. “It didn’t mean they were all going to be perfect … but they really thought outside the box.”

The tasks facing Bass and city officials are more daunting.

In Paris, the mayor talked about holding a “no-cars Games,” saying that spectators might be required to take public transportation to events. That would require a massive expansion of the current rail and bus system.

Organizers prefer the term “public-transit-first,” saying there will be parking at some venues, but not at others. Fans who want to drive themselves might have to use temporary satellite lots and take shuttle buses.

When reporters asked Bass about homelessness in Southern California, she pushed back on the idea of waiting until the last few weeks before the Games and conducting sweeps to get people off the streets.

“We are going to get Angelenos housed,” she said. “That is what we have been doing and we’re going to continue to do that.”

When the “Flag Flight” charter finally landed at Los Angeles International Airport, taxiing to a hangar away from the main terminals, the mood was celebratory, perhaps a calm before the storm. Bass waved the Olympic flag as she emerged from the plane.

Gov. Gavin Newsom and a horde of media waited for her on the tarmac.

“It’s really going to kick us into high gear,” she said. “And I am hoping that this will be the spark in our city for everybody to get excited.”