(TNND) — The country is looking for answers after an Army helicopter crashed midair with a passenger jet carrying 64 people, leaving no survivors, Wednesday night at Ronald Reagan National Airport near Washington, D.C.

Three soldiers were on board the helicopter when it collided with the American Airlines jet arriving from Wichita, Kansas.

Both aircraft ended up in the Potomac River. Dozens of bodies have been pulled from the icy waters.

President Donald Trump addressed the nation Thursday morning “in an hour of anguish.”

“As one nation, we grieve for every precious soul that has been taken from us so suddenly,” Trump said.

Aviation safety expert Daniel Kwasi Adjekum called it a “very sad day for aviation in America.”

Adjekum, a professor of aviation and aerospace sciences at the University of North Dakota, said his heart aches for those affected by this crash.

And he said the lessons learned from this tragedy should make flying safer for everyone in the future.

MORE: What we know about the victims of American Airlines plane and Army helicopter crash in DC

The military, the National Transportation Safety Board and the Federal Aviation Administration are investigating.

“I believe the NTSB should be able to come up with findings and recommendations that will avert this unfortunate and catastrophic event” from repeating itself, Adjekum said.

Pilot Mark Weinkrantz told The National News Desk’s Jan Jeffcoat that flying remains very safe in America.

“I'd go down to the aircraft and put my children on a plane today,” he said.

Every day, the FAA oversees over 45,000 flights with nearly 3 million passengers.

And there’s not been a fatal crash involving a major U.S. airline since 2009.

So, how did this tragedy happen?

That’s for the NTSB-led investigation to determine, but both Adjekum and Weinkrantz shared their expert insights based on early publicly reported information.

Visibility was good on a clear night over Washington.

Adjekum said the air traffic controller asked the passenger jet to sidestep to a different runway as it approached the airport.

Weinkrantz said both the jet and helicopter, a UH-60 Blackhawk, were on normal flight patterns in an incredibly congested airspace.

“It's just two aircraft that should not have overlapped at the same point, at the same altitude, at the same time, did that last night, unfortunately,” Weinkrantz said. “And we're seeing the consequences this morning.”

Adjekum said the passenger jet’s sidestep to a different runway “is a purely visual maneuver.”

At the same time, the Army helicopter was approaching.

Defense Secretary Pete Hegseth said in a video posted to social media that the “fairly experienced crew” was on an annual proficiency training flight.

The helicopter crew had night-vision goggles, Hegseth said.

Adjekum said the night-vision goggles may have been a factor in the crash.

The goggles, of course, amplify light in low-light environments.

When there’s extreme light stimulus, the goggles might be equipped to minimize the intensity for the wearer.

Some models might even momentarily shut off to readjust, Adjekum said.

An air traffic controller tried to confirm with the helicopter crew that they had seen the passenger jet and to get the soldiers to pass behind the jet.

Adjekum said the plane would’ve had a lot of external lights on during its landing approach, which potentially could have overwhelmed the night-vision goggles and momentarily blinded the soldiers, if they were actively using the night-vision goggles.

The helicopter crew might have lost sight of the plane.

Or they might have lost situational awareness, Adjekum said.

And the helicopter might’ve been in the plane’s blind spot.

The whole situation unfolded in a matter of 30 seconds or less, Adjekum said.

Weinkrantz also mentioned lights and motion as possible contributing factors – ground lights, stars, moving aircraft, and cars moving on the ground.

“There's a lot of clutter out there,” Weinkrantz said. “And it's difficult, even for an experienced pilot, to sometimes pick out an aircraft they're supposed to see.”

Weinkrantz said it was possible the helicopter saw the wrong plane when contacted by the tower.

Meanwhile, Weinkrantz said the pilots of the plane would’ve been focused on landing.

A preliminary FAA report obtained by The Associated Press said one air traffic controller was working two positions at the time of the crash, the AP reported Thursday afternoon.

Adjekum said we’ll learn more about what technology each aircraft had, including traffic collision and avoidance systems.

He said avoidance systems could also be inhibited by the low altitude at which the aircraft were flying at the time of the collision.

The NTSB will also be looking at the human factors involved in the crash, such as possible fatigue at night that could’ve impacted response time.

The NTSB will retrieve the flight data and cockpit voice recorders. Investigators will interview the air traffic controllers. And they’ll analyze videos from vantage points around the airport.

Adjekum said we should have a preliminary report in about a month.

A final report with recommendations should come within a year.

“We learn a lot from every safety event, incident and accident,” Adjekum said.