FBI UFC investigation, explained: What to know about alleged drone attack plan at Donald Trump's White House card

Donald Trump's ambitious UFC card on the White House lawn largely went off without a hitch, as rain stayed away, but the FBI and Secret Service say it could have taken a dark time if not for a heroic mother.

One mom's actions helped law enforcement foil an alleged terror plot that would have targeted the event with explosive-laden drones and snipers.

Five individuals have been charged in connection with the alleged plot.

Here's what you need to know about the FBI's investigation.

MORE: Full results from UFC Freedom 250 card at White House

FBI UFC investigation

The FBI announced Tuesday that it arrested five individuals across four different states after foiling an alleged terror plot that would have attacked attendees of the UFC Freedom 250 card at the White House on Sunday.

"On June 10, FBI and our law enforcement partners became aware of a potential threat to the UFC America 250 event in Washington, D.C. involving individuals outside of the National Capital Region — and thanks to the rapid action of this FBI, our partners, and the Department of Justice in a multi-state operation, multiple individuals are now in custody and allegedly planned attacks were stopped cold,” FBI Director Kash Patel said in a release.

The plot, according to the FBI, would have used drones laden with explosives to spark panic and send attendees fleeing, at which point snipers would have targeted the crowd. The area around the octagon seated about 4,300 people, but an estimated 85,000 fans watched the event on large screens erected on the Ellipse just to the south of the White House.

The FBI says those participating in the alleged plan "expressed ultra-religious and antigovernment sentiments." 19-year-old Tycen Proper, whose mom helped foil the plot by alerting authorities to concerning messages her son sent and stashes of weapons he acquired, told law enforcement that he aimed to "jump-start" a revolution and target politicians.

"The co-conspirators had electronic chats on encrypted social media platforms. In those chats, members of the group allegedly discussed assassinating several U.S. Senators, Representatives, and prominent business executives," the FBI said in a release. "Members of the group targeted some legislators based on the group’s perceived belief that the legislators accepted money from pro-Israel lobbies."

None of the individuals charged made it to Washington D.C., and the UFC Freedom 250 card still went on as planned despite law enforcement not disclosing the alleged plot until Tuesday.