Washington -- After days of mounting pressure, the U.S. on Wednesday grounded all Boeing 737 Max jets, the aircraft involved in a deadly crash in Ethiopia. President Trump announced that the Federal Aviation Administration had ordered U.S. airlines to remove the popular passenger jet from service temporarily, but it gave no end date for the move. The decision followed bans in dozens of other countries.

The FAA said the decision was based on new information about the crash of the Ethiopian Airlines Boeing 737 Max 8 on Sunday that killed 157 people.

The jet's "black boxes" -- the flight data and cockpit voice recorders -- arrived in Paris overnight to be read. CBS News correspondent Kris Van Cleave was at Reagan National Airport outside Washington on Thursday morning, where some of the grounded Max jets were parked.

When the FAA decision was made, the 72 Max planes flown by Southwest, American, and United were told to stay put at the airport they were at or were flying into. All three carriers were scrambling on Thursday to make up the roughly 280 flights per day that those aircraft handled.

"I'm just relieved we're on the ground," said Southwest Airlines passenger Percilla Tremie after she touched down in Phoenix on a Southwest Airlines Boeing 737 Max on Wednesday. Her flight from Houston took off just minutes before President Trump announced the FAA's decision to ground the planes.

"The safety of the American people and all people is our paramount concern," Mr. Trump said on Wednesday.

The U.S. was among the last of more than 40 countries to temporarily ban the 737 Max planes. Federal regulators and airlines had been facing increasing pressure to ground the jets following Sunday's crash of Ethiopian Airlines Flight 302 -- the second 737 Max 8 to crash in less than five months.

On Tuesday, the FAA said it had no basis to ground the Max, but on Wednesday, the agency reversed course, saying it had received new satellite data that showed the flight track of Flight 302 was similar to that of the Lion Air 737 Max that crashed off of Indonesia in October. Both planes struggled to maintain altitude in the minutes after takeoff.

Evidence found at the crash site outside the Ethiopian capital of Addis Ababa showed additional similarities.

But former FAA assistant administrator Scott Brenner told Van Cleave the agency still should have waited for data from the Ethiopian jet's black boxes before making its decision.

"You're grounding a class of aircraft base on nothing but political pressure," he said, adding that while the FAA has, "always been a very cooperative, data-driven group, and now that seems to have kind of gone to the wayside."

Ethiopian investigators have now sent the black boxes to Paris to be analyzed -- nearly three days after they were recovered from the crash site.

Former NTSB investigator Jeff Guzzetti told CBS News the readout should have happened much sooner, and the fact that it didn't is "negligent in my view."

"Time is of the essence," Guzzetti said.

Ethiopian officials originally asked Germany to analyze the black boxes, but the Germans lack the necessary software. American Airlines has said it will start ferrying some of their Max planes back to their bases today.

Boeing, meanwhile, said it remains confident in the safety of the 737 Max planes, but supports the grounding out of an abundance of caution.