VP’s husband, Doug Emhoff, will attend a 9/11 ceremony in Shanksville, Pa.

Second gentleman Doug Emhoff on Monday will participate in a memorial service in Shanksville, Pennsylvania, to honor those who died on Flight 93 after it was hijacked on Sept. 11, 2001.

Mr. Emhoff had been scheduled to attend a ceremony in New York City with his wife, Vice President Kamala Harris, who will still be at the National September 11 Memorial and Museum in Manhattan while the second gentleman is in rural Pennsylvania.

Flight 93 was one of four commercial flights hijacked by Islamic terrorists during the 2001 attacks. Two flights hit the World Trade Center and another crashed into the Pentagon, though Flight 93 passengers were credited with keeping the plane away from a Washington target — perhaps the U.S. Capitol — before it crashed in Shanksville.

Mr. Emhoff’s appearance at the Flight 93 National Memorial Observance Wreath Laying Ceremony means four principal figures from the White House will mark the 22nd anniversary of the attacks in separate places.

First lady Jill Biden, who is overcoming a COVID-19 infection this week, is scheduled to lay a wreath at the National 9/11 Pentagon Memorial.

In an unusual twist, Mr. Biden will mark the anniversary with military members in Anchorage, Alaska, as he returns from a trip to India and Vietnam.