Relatives have been wailing and beating their chests at the site of the Ethiopian Airlines crash as others picked through the rubble for any sign of the 157 people who died. That flight crashed into the Java Sea off Indonesia in October, killing 189 people.
The US Federal Aviation Administration was under intense pressure to ground the planes and resisted even after Canada relented on Wednesday and agreed to bar the Max from the air, leaving the US nearly alone.
The Max is the latest upgrade to the Boeing 737s. "But it will temporarily stop delivering 737 Max jets to airlines as Boeing determines what caused two of those planes to crash within the past six months".
Pilots were waiting anxiously for the investigation.
With heightened global scrutiny, the head of Indonesia's transport safety committee said a report into the Lion Air crash would be speeded up for release in July or August. "The investigation team will decide where", the spokesman told Reuters.
Major disruptions have not been reported in other countries where the Max has been grounded.
French authorities have the flight data and cockpit voice recorders, though Ethiopia is formally leading the investigation and USA experts are in Paris and Addis Ababa too.
Thousands of kilometres away, distraught families were demanding answers as they visited the deep black crater where the plane smashed into a field outside the capital, disintegrating on impact.
"There is no capacity here so the black box will be sent elsewhere for analysis".
Separately, the New York Times reported that doomed Ethiopian Airlines Flight 302 to Nairobi was in trouble nearly immediately after takeoff as it lurched up and down by hundreds of feet at a time.
Though it maintains the planes are safe, Boeing has supported the FAA move.
Trump told reporters the "safety of the American people and all peoples is our paramount concern".
FAA acting chief Daniel Elwell said the agency has been "working tirelessly" to find the cause of the accident but faced delays because of the damage to the flight data recorders.
"In addition to the basic trainings given for 737 aircraft types, an additional training was given for the Max version", Tewolde said.
Boeing shares have lost 12%, or $28 billion in market value, since Ethiopian flight 302 went down on March 10. "That is the main challenge we have now", Gebremariam said.
The MAX series is Boeing's fastest-selling model, but it is still relatively new with fewer than 500 in service.
One said the flight crew reviewed the incident "at length. but can't think of any reason the aircraft would pitch nose-down so aggressively".
Investigators looking into the Indonesian crash are examining whether the software automatically pushed the plane's nose down repeatedly, and whether the Lion Air pilots knew how to solve that problem.
The US Federal Aviation Administration grounded the planes on Wednesday, saying regulators had new satellite evidence that showed the movements of Ethiopian Airlines Flight 302 were similar to those of Lion Air Flight 610.
Japanese airlines do not use the aircraft.
Boeing was criticised after the Lion Air crash for allegedly failing to adequately inform 737 pilots about the functioning of the stall prevention system.
The captain asked in a panicky voice to turn back only three minutes into the flight as the plane accelerated to abnormal speeds, the newspaper reported, citing a person who reviewed the jet's air traffic communications.