HEJERE, Ethiopia -- Airlines in Ethiopia, China, Indonesia and elsewhere grounded the Boeing 737 Max 8 jetliner Monday after the second devastating crash of one of the planes in five months. But Boeing said it had no reason to pull the popular aircraft from the skies.
As the East African country mourned the 157 victims of the Ethiopian Airlines plane that went down in clear weather shortly after takeoff Sunday, investigators found the jetliner's two flight recorders at the crash site outside the capital of Addis Ababa.
An airline official, however, said one of the recorders was partially damaged and "we will see what we can retrieve from it." The official spoke on condition of anonymity for lack of authorization to speak to the media.
A witness to the crash told The Associated Press that smoke was coming from the rear of the plane before it hit the ground.
"Before falling down, the plane rotated two times in the air, and it had some smoke coming from the back then, it hit the ground and exploded," Tamrat Abera said. "When the villagers and I arrived at the site, there was nothing except some burning and flesh."
Ethiopian authorities are leading the investigation into the crash, assisted by the U.S., Kenya and others.
The crash was similar to that of a Lion Air jet of the same model in Indonesian seas last year, killing 189 people. The crash was likely to renew questions about the 737 Max 8, the newest version of Boeing's single-aisle airliner, which was first introduced in 1967 and has become the world's most common passenger jet.
Safety experts cautioned against drawing too many comparisons between the two crashes until more is known. Besides the groundings by airlines in Ethiopia, China and Indonesia, Caribbean carrier Cayman Airways, Comair in South Africa and Royal Air Maroc in Morocco temporarily grounded their Max 8s.
Ethiopian Airlines decided to ground its remaining four 737 Max 8s until further notice as "an extra safety precaution," spokesman Asrat Begashaw said. The carrier had been using five of the planes and awaiting delivery of 25 more.
But Chicago-based Boeing said it did not intend to issue any new recommendations about the aircraft to its customers. It plans to send a technical team to the crash site to help investigators and issued a statement saying it was "deeply saddened to learn of the passing of the passengers and crew" on the jetliner.
Among the airlines still using the plane are Southwest, American and Air Canada.
In Washington, Transportation Secretary Elaine L. Chao said passenger safety was the first priority for the administration.
"I want travelers to be assured and that we are taking this seriously and monitoring latest developments," she said.
It's unusual for authorities to take the step of grounding planes, and it's up to each country to set standards on which planes can fly and how those planes are maintained, said Todd Curtis, an aviation safety analyst who directs the Airsafe.com Foundation.
"If there is a suspicion ... that there's not only something inherently wrong with 737 Max 8 aircraft, but there are no procedures in place to cure the problem, then yes, they should either ground the plane, or there are several levels of things they could do," Curtis said.
People from 35 countries died in the crash six minutes after takeoff from Ethiopia's capital for Nairobi. Ethiopian Airlines said the senior pilot issued a distress call and was told to return but all contact was lost shortly afterward. The plane plowed into the ground at Hejere near Bishoftu, scattering debris.
"I heard this big noise," resident Tsegaye Reta told the AP. "The villagers said that it was a plane crash, and we rushed to the site. There was a huge smoke that we couldn't even see the plane. The parts of the plane were falling apart."
Kenya lost 32 people, more than any country. Relatives of 25 of the victims had been contacted, Transport Minister James Macharia said, and taking care of their welfare was of utmost importance.
"Some of them, as you know, they are very distressed," he said. "They are in shock like we are. They are grieving."
In Addis Ababa, members of an association of Ethiopian airline pilots wept uncontrollably for their dead colleagues. Framed photos of seven crew members sat in chairs at the front of a crowded room.
The flight's main pilot, Yared Getachew, issued a distress call shortly after takeoff and was told to return, but all contact was lost.
Canada, Ethiopia, the U.S., China, Italy, France, Britain, Egypt, Germany, India and Slovakia all lost four or more citizens.
At least 21 staff members from the United Nations were killed in the crash, said U.N. Secretary-General Antonio Guterres, who led a moment of silence at a meeting where he said "a global tragedy has hit close to home."
Both Addis Ababa and Nairobi are major hubs for humanitarian workers, and some had been on their way to a large U.N. environmental conference set to begin Monday in Nairobi. The U.N. flag at the event flew at half-staff.
The crash shattered more than two years of relative calm in Africa, where travel had long been chaotic. It also was a serious blow to Ethiopian Airlines, which has expanded to become the continent's largest and best-managed carrier and turned Addis Ababa into the gateway to Africa.
The state-owned carrier has a good reputation and the company's CEO told reporters no problems were seen before Sunday's fight. But investigators also will look into the plane's maintenance, which may have been an issue in the Lion Air crash.
The plane was delivered to Ethiopian Airlines in November. The jet's last maintenance was on Feb. 4, and it had flown just 1,200 hours.
China's Civil Aviation Administration said that it ordered airlines to ground all 737 Max 8 aircraft as of 6 p.m. (1000 GMT) Monday, in line with the principle of "zero tolerance for security risks."
It said it would issue further notices after consulting with the U.S. Federal Aviation Administration and Boeing.
China Southern Airlines is one of Boeing's biggest customers for the aircraft.
Comair, the operator of British Airways and Kulula flights in South Africa, said it has grounded its Boeing 737 Max 8 while it consults with Boeing, other operators and technical experts. The statement did not say how many planes are affected. Wrenelle Stander, executive director of Comair's airline division, said that Comair "remains confident in the inherent safety of the aircraft."
An official with Royal Air Maroc said the carrier in Morocco has halted the commercial use of its sole operational model, pending tests and examinations. The official, who spoke on condition of anonymity in line with departmental rules, said the plane was scheduled to fly on Monday from Casablanca to London but was replaced.
The 737 is the best-selling airliner in history, and the Max, the newest version of it with more fuel-efficient engines, is a central part of Boeing's strategy to compete with European rival Airbus.
"Safety is our No. 1 priority and we are taking every measure to fully understand all aspects of this accident, working closely with the investigating team and all regulatory authorities involved," Boeing said in a statement.
Boeing's stock fell 7 percent to $391.80 in afternoon trading.