A loud noise that was heard across much of the Washington, D.C., area on Sunday afternoon, was caused by the sonic boom from military jets scrambling to respond to an intrusion into restricted airspace by a private flight, military and U.S. officials confirmed on Sunday.
Two fighter jets were sent from Joint Base Andrews, after a Cessna entered the restricted airspace, prompting the emergency response to intercept the flight, the officials confirmed on Sunday.
The North American Aerospace Defense Command, which oversees aerospace control over the United States and Canada, said in a statement that two F-16 jets were deployed after the Cessna 560 Citation V flew over Washington and Northern Virginia.
NORAD said that the fighter jets “were authorized to travel at supersonic speeds,” which would have produced the boom heard in the region, and that by some reports was noticed as far as the suburbs of Virginia and Maryland. The NORAD aircraft also used flares that may have been visible from the ground, the agency said, “in an attempt to draw attention from the pilot.”
After the Cessna veered into the restricted area, which includes important national landmarks, the Federal Aviation Administration called the pilot but received no response from that plane, and the military ordered the jets to intercept, a military official said.
Officials later determined that the Cessna plane did not pose a threat, and the investigation would look into why the pilot did not respond to the F.A.A. The Cessna was not shot down, the officials said.
The Cessna crashed near the George Washington National Forest in Virginia, NORAD said, though an earlier statement from the F.A.A. said it “crashed into mountainous terrain in a sparsely populated area of southwest Virginia,” near Montebello, around 3:30 p.m. local time.
The aircraft had taken off from Elizabethton Municipal Airport in Elizabethton, Tenn., and was bound for Long Island MacArthur Airport in Ronkonkoma, N.Y., the agency said, adding that the incident was under investigation. The Cessna Citation bound for the Long Island airport left Tennessee at 1:13 p.m., according to the flight-tracking website Flight Aware.
The condition of anyone onboard was not immediately clear.
The Annapolis Office of Emergency Management had also said on Twitter that the sonic boom resulted from an authorized Defense Department flight.
Shortly after the incident, people reported on social media that they had heard a loud boom in Washington, and in Maryland and Northern Virginia. Many said the noise sounded like an explosion, and some said the boom was so strong that it shook their homes. A sonic boom is caused by an object moving faster than sound, or about 750 miles per hour at sea level.
The noise from the sonic boom startled people across the Washington area and many took to social media to speculate about what could have caused it.
Rafael Olivieri, 62, said he was at home in Annandale, Va., when he heard a “loud, very short sound” that shook his house. Mr. Olivieri ran outside, where his neighbors were also trying to figure out what had happened. “My first thing was looking to the sky,” he said. “I was really worried.”
More than 30 miles northeast in Edgewater, Md., Joseph Krygiel, 47, also felt the boom. He said he was in his basement just after 3 p.m. when the whole house shook. “It felt like something major,” Mr. Krygiel said.
Washington’s Homeland Security and Emergency Management Agency also acknowledged the boom.
“We are aware of reports from communities throughout the National Capital Region of a loud ‘boom’ this afternoon,” the agency said on Twitter. “There is no threat at this time.”