Randy Gentry, a representative from Pence’s office, announced the event was canceled.

“There’s been an emergency callback,” Gentry told those waiting. “The vice president was asked to return to Washington so at this time we’re going to cancel today’s event.”

Farah, however, said Pence never left Washington.

“There was no “emergency callback,” she tweeted.

A Defense official confirmed that the aircraft never took off from Joint Base Andrews in Maryland. The flight was cancelled by the requestor, the official said. 

…A White House official confirmed there was no medical issue related to the president or the vice president.

Mike Pence abruptly cancels New Hampshire trip, reason unclear

WTF?