A couple known for scaling some of the world’s tallest skyscrapers is expected to appear in a Manhattan court on Thursday after allegedly climbing to the top of the Empire State Building in what they described as an engagement stunt.

Authorities said Angelina Nikolau, 33, and Ivan Kuznetsov, 32, both Russian nationals with a listed address in East Orange, New Jersey, spent the night in separate holding cells at the Manhattan Criminal Court building on Centre Street following their arrest.

The Manhattan District Attorney’s Office was reviewing the case and preparing formal criminal charges overnight.

Investigators, along with Empire State Building security officials, are examining surveillance footage to determine how the pair gained access to the landmark and bypassed security screening before reaching the observation deck.

According to the New York City Police Department, Nikolau and Kuznetsov climbed onto the building’s iconic spire, where they remained for several minutes while recording videos of the stunt before descending.

The pair have built a large online following through videos documenting their unauthorized climbs of skyscrapers and other high-rise structures around the world, often performing dangerous feats at extreme heights.

Authorities continue to investigate the incident, and the couple is expected to make its initial court appearance on Thursday.