Travel in France was disrupted hours before the Paris Games opening ceremony on Friday when arsonists set fire to three high-speed rail lines.

Numerous trains were canceled on Friday morning, and the railway company S.N.C.F. urged travelers to delay their plans, The New York Times reported. The fires started in towns nearly 100 miles outside of Paris and were set in pipes that hold cables used for signaling, according to S.N.C.F. Chief Executive Jean-Pierre Farandou. No one has claimed responsibility.

“The investigation is starting, I call on everyone to be cautious,” said French Prime Minister Gabriel Attal. “What we know, what we see, is that this operation was prepared, coordinated, that nerve centers were targeted, which shows a certain knowledge of the network to know where to strike.”

The arson attacks happened as French authorities have been ramping up security around Paris in anticipation of the Olympic Games, with around 55,000 police and soldiers monitoring the capital city, Reuters reported. Authorities expect to see more than 300,000 spectators gather near the River Seine for the opening ceremony.

Along with thousands of spectators having to change their plans, some Olympic athletes were also caught up in the commuting nightmare following the arson attacks. Two German athletes were forced to turn back after the rail line closures, and will likely miss the opening ceremony, according to the Associated Press, which cited a German news agency.

Police have also taken proactive security measures before the Games, targeting 155 people deemed potential threats and essentially placing them under house arrest, according to the Times. French authorities arrested a man in May for allegedly planning on carrying out an attack outside of an Olympic soccer match in the southern town of Saint-Étienne. A Russian man was also arrested on suspicion of attempting to “destabilize the Olympic Games.”

French Interior Minister Gérald Darmanin said that 5,000 people who had applied to work numerous different jobs during the competitions, such as security and stadium workers, were rejected when criminal records flagged them for “radicalization.” France has also requested the help of U.S. security. Officers from New York and Los Angeles, along with bomb-sniffing dogs, will be joining the security forces at this year’s Olympic Games in Paris, The Wall Street Journal reported.

Bruno Le Ray, a retired general who is in charge of Olympics security, said, “The security measures and the resources deployed for the Games’ opening ceremony are unprecedented.”

Former President Barack Obama endorsed Vice President Kamala Harris in a video posted to X in the early morning hours on Friday.

The post went live at 5:01 am ET, which meant 2:01 am on the West Coast.

“Earlier this week, Michelle and I called our friend Kamala Harris,” Obama said in the post. “We told her we think she’ll make a fantastic President of the United States, and that she has our full support. At this critical moment for our country, we’re going to do everything we can to make sure she wins in November. We hope you’ll join us.”

Earlier this week, Michelle and I called our friend @KamalaHarris. We told her we think she’ll make a fantastic President of the United States, and that she has our full support. At this critical moment for our country, we’re going to do everything we can to make sure she wins in… pic.twitter.com/0UIS0doIbA

— Barack Obama (@BarackObama) July 26, 2024

The post included a video of Harris walking around with a cell phone as Barack and Michelle Obama gush about her.

“Michelle and I couldn’t be prouder to endorse you and to do everything we can to get you through this election and into the Oval Office,” the former president says in the video.

“Oh my goodness. Michelle, Barack, this means so much to me. I’m looking forward to doing this with the two of you, Doug and I both. And getting out there, being on the road,” Harris replied.

Michelle also said she was proud of Harris.

“I can’t have this phone call without saying to my girl, Kamala, I am proud of you. This is going to be historic,” she told the vice president.

Along with the video, the Obamas also released a joint statement endorsing Harris, according to CNN.

“But Kamala has more than a resume,” the statement said, according to the outlet. “She has the vision, the character, and the strength that this critical moment demands. There is no doubt in our mind that Kamala Harris has exactly what it takes to win this election and deliver for the American people.”

Unlike many Democrats who quickly endorsed Harris following President Joe Biden’s announcement that he was ending his re-election campaign, Obama was noticeably silent for five days. Instead, Obama released a statement following Biden’s announcement: “I have extraordinary confidence that the leaders of our party will be able to create a process from which an outstanding nominee emerges.”

Even though around 14 million Democrat voters chose Biden as their 2024 presidential nominee, the party has adopted rules allowing a remote voting process to select a replacement nominee by August 7. Nearly 2,000 delegates already pledged to Biden – and voted for by the people – have already switched to Harris.

“While this situation is unprecedented, the process we are prepared to undertake is not,” Democratic National Convention Chair Minyon Moore said Monday, according to CNN. “We have important deadlines to meet. We will make sure the process is fair, because, as it stands, no candidate has secured a majority of the delegates to the convention.”

Democratic National Committee Chair Jaime Harrison also claimed that this process, which circumvents the will of the voters, “reflects the dedication to democracy our party stands for.”