President Donald Trump and First Lady Melania Trump encountered an unexpected hiccup on Tuesday morning when an escalator at United Nations headquarters in New York suddenly stopped while they were on it. The pair calmly continued on foot before Trump delivered his scheduled address to the General Assembly.

White House Press Secretary Karoline Leavitt quickly called for an investigation, citing reports that some UN staff had previously joked about limiting elevator and escalator access during Trump’s arrival.

In comments later that evening, she suggested the incident “appears” suspicious and urged accountability if intentional interference were discovered. The U.S. Secret Service has confirmed it is reviewing the matter.

UN officials, however, dismissed the notion of sabotage. Spokesman Stéphane Dujarric explained that the stoppage was triggered by a built-in safety mechanism after a U.S. delegation videographer, walking backward to capture footage, stepped incorrectly near the top. READ MORE BELLW