What is a sonic boom? Blast heard across Washington, D.C., after F-16 fighter jets scramble to intercept plane

A sonic boom that rattled residents in the Washington, D.C., area Sunday was caused by F-16 fighter jets scrambling to intercept an unresponsive small plane that later crashed in rural Virginia, killing all four people on board, federal officials say.

Here’s everything we know about the sound that clattered windows and shook houses across two states, and the unusual incident that led to it.

What is a sonic boom?

According to NASA, a sonic boom happens when “shock waves from an object traveling through the air faster than the speed of sound” — or about 750 miles per hour — “merge together before they reach the ground.”

And they “generate enormous amounts of sound energy about 110 decibels, like the sound of an explosion or a thunderclap.”

That’s precisely what people from Maryland to Virginia said they heard Sunday, with many flocking to social media asking what had happened.

Some even inadvertently captured recordings of the boom.

Footage from a home security camera in Fairfax Station, Va., posted to social media showed a dog, Rocket, awoken and startled by the sound as he slept on an outdoor deck. And video taken by musicians rehearsing indoors in Fairfax showed them startled by the sound.

Read more on Yahoo News: Sonic boom rattles Washington as fighter jets chase Cessna (AFP)

What led to this one?

According to the Federal Aviation Administration, the plane, a Cessna 560 Citation V, took off from Elizabethton, Tenn., around 1:15 p.m. and was headed for MacArthur Airport in Long Island, N.Y.

But the aircraft inexplicably turned around before it landed, flying southwest along the Atlantic Coast and over restricted airspace around the nation’s capital.

According to the North American Aerospace Defense Command (or NORAD), six F-16 jets from three locations were launched to intercept the plane, which was not responding to radio transmissions.

The U.S. Capitol was “briefly placed on an elevated alert until the airplane left the area,” the U.S. Capitol Police said.

The fighter jets intercepted the plane around 3:20 p.m., about 10 minutes before it crashed.

In a statement, NORAD said the F-16s were authorized to travel at supersonic speeds, which resulted in the sonic boom that reverberated across the D.C. metro area.

“The NORAD aircraft were authorized to travel at supersonic speeds, and a sonic boom may have been heard by residents in the region,” NORAD said, adding that the F-16s fired off flares in an attempt to draw attention to the unresponsive pilot.

Did Biden hear it?

He did.

Officials in Bowie, Md., said Sunday that an aircraft that had flown out of Joint Base Andrews caused the sonic boom. At a press briefing Monday, National Security Council spokesman John Kirby said that two of the scrambled jets took off from the base and were the first to reach the Cessna.

"They had to turn on the speed to get to it, which is why people here in the District area heard a sonic boom," Kirby said. "They had to break the sound barrier to get up to speed to get to the aircraft in question."

According to a White House official, President Biden was playing golf at Joint Base Andrews with his brother around the time that the fighter jets took off.

Biden had been briefed on the incident, the official said, adding that the sound of the scrambling aircraft could be faintly heard at the base.

What caused the crash?

It is unclear, but the owner of the plane said rapid depressurization is a possible cause.

Flight tracking sites showed the jet suffered a rapid spiraling descent, dropping at a rate of more than 30,000 feet per minute before crashing in the St. Mary’s Wilderness near the George Washington National Forest.

Virginia State Police said officers were notified of the potential crash shortly before 4 p.m. and rescuers reached the crash site by foot around four hours later.

No survivors were found.

Read more on Yahoo News: No survivors found after plane that flew over D.C. and led to fighter jet scramble crashes in Virginia (AP)

Who was on the plane?

The plane was registered to Encore Motors of Melbourne Inc., a Florida-based company owned by Barbara and John Rumpel.

John Rumpel told multiple news outlets that his daughter, 2-year-old granddaughter, her nanny and the pilot were aboard the plane, and that they were returning to their home in East Hampton after visiting his house in North Carolina.

Rumpel, a pilot, told the New York Times that authorities did not know the cause of the crash or why it turned around but suggested a loss of cabin pressure could have rendered the pilot and passengers unconscious.

The incident drew comparisons to the 1999 crash of an unresponsive Learjet that flew aimlessly across the country before crashing in rural South Dakota, killing all six people on board, including professional golfer Payne Stewart.

Investigators concluded that cabin depressurization and hypoxia, or loss of oxygen, caused everyone aboard Stewart’s plane, including the pilot, to lose consciousness.