WASHINGTON (NewsNation) — The Senate Commerce Committee announced Wednesday that the panel plans to review the cause of a Federal Aviation Administration computer system outage that sparked a nationwide ground stop.

Thousands of U.S. flights were delayed or canceled Wednesday, according to FlightAware.

“We will be looking into what caused this outage and how redundancy plays a role in preventing future outages,” Senate Commerce Committee Chair Maria Cantwell said. “The public needs a resilient air transportation system.”

The ground stop was lifted shortly before 9 a.m. ET.

White House Press Secretary Karine Jeane-Pierre said the White House does not have evidence that the outage was caused by a cyber attack. However, President Joe Biden directed the Department of Transportation to conduct a full investigation into the cause, she added.

While the White House did call the investigation a “top priority,” it rejected a lack of confidence in the system.

“What you saw happened today was out of an abundance of caution,” Jeane-Pierre said. “The safety of Americans is a priority.”

As Congress is still being briefed about the NOTAM computer system failure, House Majority Leader Rep. Steve Scalise, R-La., said he doesn’t feel that new rules or regulations need to be added, but officials do need to figure out what caused this issue.

“Incompetence is not an excuse to increase regulation. You gotta go fix the problem. At the end of the day, if you’ve got a referee out on the field, and the players can’t perform, you get rid of the players, you don’t add more rules to the rulebook,” Scalise told NewsNation. “Frankly, I think the rules already are making it harder for people to do their job, but there’s some people that aren’t up to the job, and that’s the problem we have right now.”

He continued: “I think (Transportation Secretary Pete Buttigieg) has got some tough questions to answer. We’re going to be bringing him in and asking him those questions. Frankly, I think a lot of people across America are going to be watching because they’re being hurt by the incompetence we’re seeing over at the Department of Transportation.”

Biden addressed the FAA issue Wednesday before leaving the White House to accompany his wife to a medical procedure at Walter Reed National Military Medical Center outside Washington. He said he had just been briefed by Buttigieg.

“I was on the phone with him for about 10 minutes,” Biden said. “I told him to report directly to me when they find out. Air traffic can still land safely, just not take off right now. We don’t know what the cause of it is.”

Speaking at the 2023 Transportation Research Board Wednesday, Buttigieg said it’s “another challenging day for U.S. aviation.”

“We are now pivoting to focus on understanding the causes of the issue,” he said. “And the main thing I want everybody to understand is that every step of the way, safety is going to be our North Star, as it always is.”

Former Vice President Mike Pence said he was one of the passengers waiting at the Indianapolis airport, waiting to come to Washington, D.C. for the day. He called on the Biden administration and the Department of Transportation to give Americans answers and demand that airlines have the necessary technology.

“To my knowledge, this was the first national groundstop since 9/11 and the American people deserve to know why it took place, what happened and also what’s being done to ensure that we have the redundancy in the system to make sure this never happens again,” Pence told The Hill.   

Republican U.S. Rep. Pat Fallon of Texas said they want to rule out any kind of cyberattack first. If this was a software glitch, he said more firewalls are needed to ensure fail-safe systems are in place so this doesn’t happen again.

“We need to know, we need to look into it, and ensure we do our due diligence to find out what the cause was,” he said. “We’re going to find out what the glitch was. We’re going to tell the American people what the glitch was and what we’re going to do to fix it.”

This is just the latest headache for travelers in the U.S. who faced flight cancellations over the holidays amid winter storms and a breakdown with staffing technology at Southwest Airlines. 

South Carolina Rep. Nancy Mace (R) said a “serious conversation” about technology and aviation is needed after these incidents.

“We want to make sure that our technology works, that our technology is safe, our technology is secure,” she said. “This cannot continue, especially with this being just on the heels of the Southwest Airlines debacle.”

If outdated technology is the issue, Mace said she wants to hear Buttigieg say that he and the FAA will come to Congress and brief them on the matter.

Fallon shared Mace’s sentiments.

“In the 21st century, we really have to talk about software and computers,” he said.

Meanwhile, the U.S. Travel Association is calling on lawmakers to “modernize” the nation’s travel infrastructure.

“Today’s FAA catastrophic system failure is a clear sign that America’s transportation network desperately needs significant upgrades. Americans deserve an end-to-end travel experience that is seamless and secure,” said U.S. Travel Association President and CEO Geoff Freeman. “And our nation’s economy depends on a best-in-class air travel system. We call on federal policymakers to modernize our vital air travel infrastructure to ensure our systems are able to meet demand safely and efficiently.”

The FAA said it is working on restoring its Notice to Air Missions System.

Before commencing a flight, pilots are required to consult NOTAM, or Notice to Air Missions, which lists potential adverse impacts on flights, from runway construction to the potential for ice. The system used to be telephone-based, with pilots calling dedicated flight service stations for the information, but has now moved online.

Breakdowns in the NOTAM system appear to be rare.

The FAA has been without a permanent administrator since March 31. Biden’s pick to head the agency, Denver International Airport Chief Executive Phil Washington, has not yet faced a hearing by the Senate Commerce Committee.

Washington has faced criticism from Republicans after he was named in a search warrant tying him to corruption allegations at the Los Angeles County Metropolitan Transportation Authority.

Meanwhile, FAA authorization is set to expire Sept. 30. Lawmakers have routinely extended the FAA legal authority to operate before reaching an agreement on authorization, but this outage may put pressure on Congress to take action.

The Associated Press and Reuters contributed to this report.