Update 10 (8:05 pm ET): Aeromexico has also grounded its Boeing 737 MAX 8s. The FAA’s safety assurances apparently haven’t been very effective outside the US.

And now California Sen. Dianne Feinstein has urged Boeing to recommend grounding 737s.

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Update 9 (7:45 pm ET): Another airline has decided to ground its Boeing 737 MAX 8s - Brazilian airline GOL.

BRAZILIAN AIRLINE GOL SUSPENDS FLIGHTS WITH BOEING 737 MAX 8

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Update 8 (5:25 pm ET): The FAA has released its 'continued airworthiness notification' for the Boeing 737 MAX 8, the latest iteration of its workhorse 737 line, certifying that the planes are safe to fly. Though it added that it is still investigating the crash of flight ET302, and will make any changes to this status "if necessary."

Full report FAA issuing a continued airworthiness notification on Boeing 737 Max 8 jets. Meaning, for now, FAA believes the Boeing 737 Max 8 jets are safe.

China, Indonesia, Ethiopia & some international carriers grounded the fleet after a second deadly crash of fairly new jets pic.twitter.com/kvHAnk3o1b — Alexandra Limon (@AlexLimonNews) March 11, 2019

No action is being taken by the FAA and the agency has found 'no link' between Sunday's crash and an October crash involving a Lion Air 737 that plunged into the Java Sea 11 minutes after takeoff. Though, suspiciously, the agency added that it anticipates "mandating changes to Boeing's 737 MAX" by April, as the aerospace company prepares to update its training manuals.

Flyers can also find succor in the fact that Boeing's CEO said he's "confident" that the 737s are safe.

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Update 7 (3:30 pm ET): Cue the panic bid.

The FAA just released a statement affirming that the Boeing 737 MAX 8 remains airworthy, and that it will act later "if needed." It also tweeted the following:

UPDATED #FAA Statement on Ethiopian Airlines Flight 302. pic.twitter.com/QJ0m5eaHHJ — The FAA (@FAANews) March 11, 2019

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Update 6: Mrs. Mitch McConnell will be looking into the Sunday Ethiopian Airlines crash involving a 737 MAX 8s. Transportation Secretary Elaine Chao said Monday that the DOT is "very concerned" about the recent Boeing crashes, is closely monitoring the situation and that she has met with FAA officials to review the crash.

U.S. DOT CHIEF CHAO MONITORING RECENT BOEING 737 MAX CRASHES

DOT `VERY CONCERNED' ABOUT RECENT BOEING 737 MAX CRASHES: CHAO

CHAO MET WITH FAA OFFICAL TO REVIEW CRASHES, PATHS FORWARD

U.S. FAA TO ISSUE NOTIFICATION ON BOEING 737 MAX SAFETY

DOT SECRETARY ELAINE CHAO REVEALS PLANS FOR MONDAY NOTICE

CHAO GAVE NO FURTHER INFORMATION ON PLANNED 5 PM NOTICE

CHAO SAID DOT STILL REVIEWING CRASH, VOWS ACTION IF NEEDED

More importantly, Chao said the DOT will issue a "safety notification" about the Boeing 737 MAX 8 at 5 pm Monday. She wouldn't reveal any more information about the announcement, but the timing - one hour after the market closes - is certainly curious.

Boeing shares, which have pared their losses throughout the day, dipped on the news. Of course, a determination that the Boeing 737 MAX isn't safe to carry passengers would be a devastating blow not just to Boeing but for the broader airline industry. The plane is a "workhouse" for dozens of aircraft carrier, and it's also Boeing's No. 1 selling plane: The company is struggling to ramp up production to 57 from 52 planes a month, with an order backlog that's literally decades long.

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Update 5: South African carrier Comair has become the latest airline to ground its 737 MAX 8s.

After facing criticism for saying it would keep its Boeing 737 MAX 8 in operation (the airline just received delivery of its first 737 MAX late last month), it has apparently decided to temporarily not schedule flights using the plane. It's reportedly in talks with Boeing.

Here is the statement the airline released a few hours ago saying it would continue to monitor the investigation into the Ethiopian Airlines crash.

Our sympathies are with those affected by the heartbreaking tragedy of the Ethiopian Airlines flight. Comair will continue to monitor the various investigations by the relevant authorities and are in close contact with both Boeing and the SACAA regarding the MAX 8 Aircraft. pic.twitter.com/3iEWGzxMqc — kulula (@kulula) March 11, 2019

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Update 4: The FAA, which is monitoring the investigation into the crash of Ethiopian Air flight ET302, is now looking into an incident involving another Boeing 737, which is a generation prior to the 737 MAX, after United Airlines flight 1168 reported engine trouble during a turbulent landing in Houston. The flight declared an emergency as it was coming in for a landing when it suddenly began experiencing engine trouble.

Here's more from the AP:

Flight 1168 was carrying 174 passengers and six crew members when engine trouble began late Sunday as the plane neared George Bush Intercontinental Airport in Houston. The Boeing 737-900 was traveling from Newark Liberty International Airport in New Jersey.

One passenger told Houston media outlets that he heard a loud bang, felt a strong vibration and saw a flash of light. Another passenger says he saw flames coming from the engine, but a Federal Aviation Administration spokeswoman says emergency responders found no evidence of fire or smoke.

The FAA has been in contact with the State Department following the Ethiopian Air crash, and plans to join National Transportation Safety Board in assisting Ethiopian authorities in investigation of crash. The union said flight attendants working for American Air won't be compelled to work on the 737s if they feel "unsafe".

Meanwhile, a former FAA official warned during an appearance on CNN that travelers should be wary about flying on 737 MAX 8s.

"I've never, ever done this. I've never said that, 'hey, it's unsafe to fly a particular model' but in this case, I'm going to have to go there... So yeah I would watch for that airplane," - fmr. FAA Safety Inspector @David_Soucie on the Boeing 737 MAX 8. https://t.co/PgcNELgjxm pic.twitter.com/qGKSt4WCru — CNN Newsroom (@CNNnewsroom) March 11, 2019

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Update 3: The flight attendants union has asked the FAA to investigate the Boeing 737 MAX 8, saying it's important to address these safety concerns after the second crash in 5 months.

*FLIGHT ATTENDANTS UNION ASKS FAA TO INVESTIGATE BOEING 737 MAX

*ASSN OF FLIGHT ATTENDANTS SEEKS ACTION AFTER SECOND MAX CRASH

*AFA: VITAL TO ADDRESS CREW, PASSENGER CONCERNS AFTER MAX CRASH

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Update 2: Boeing fell to its lows of the session after the open, with shares of the aerospace company and Dow component down 13%, its largest intraday drop since 2001. Concerns about the safety of Boeing's 737 MAX 8 are weighing on shares of airlines and Boeing suppliers more broadly as well.

Boeing has almost single-handedly dragged the Dow deep into the red, with Dow futures down 270 points while the S&P and Nasdaq remained in positive territory.

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Update: Indonesia's Transport Ministry will order the temporary grounding of all 737s while it carries out safety inspections, Reuters reported.

Reuters: #Indonesia's transport ministry says to temporarily ground #Boeing 737 MAX 8 aircraft while it undertakes inspections — Vincent Lee (@Rover829) March 11, 2019

In a sign that more details about the crash could soon be known, Ethiopian State TV says it has recovered both 'black boxes' from flight ET302, which contains important data that could shed some light on what caused the crash. Included in the data is a cockpit recording which could shed some light on what pilots were saying and doing in the plane's final moments.

Reuters: #Ethiopia State TV says black box from #EthiopianAirlines flight that crashed Sunday has been recovered — Vincent Lee (@Rover829) March 11, 2019

This could be the first major breakthrough in the investigation, and could reveal whether reported "abrupt dives" due to faults in the plane's flight-monitoring system, which was suspected of causing the Lion Air crash, were to blame.

As of 8:50 am ET, Boeing shares had dropped 11% in premarket to their lowest level of the day, dragging Dow futures down with them.

With Boeing headed for its biggest drop in at least eleven years, Dow futures are down 200 points while the S&P and Nasdaq look set for a higher open.

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Boeing ADRs traded on Germany's Tradegate exchange in Stuttgart slumped more than 9% early Monday as Chinese and Ethiopian airlines grounded their fleets of Boeing 737 MAX 8s as experts question the plane's safety after an unprecedented series of crashes. Meanwhile, Boeing opened more than 10% lower in the US premarket, weighing heavily on Dow futures, which were off by triple digits.

While some airlines opted not to ground their fleets following Sunday's devastating crash, where an Ethiopian Airlines flight dropped out of the sky six minutes after takeoff, killing everyone on board - including nearly 160 passengers and crew (including 8 Americans) - the fact that the Ethiopian Air crash happened so soon after a similar crash involving a 737 operated by Indonesia's Lion Air has raised questions about the model's safety.

On Monday (local time, late Sunday in New York), China's Civil Aviation Administration of China said all Chinese airlines must suspend their use of the 737 MAX 8 by 10 am London Time.

The CAAC said flights would not resume until Boeing had proven that no design flaw contributed to the crashes. China's regulator said it would notify airlines as to when flights could resume, after it has heard back from Boeing and the FAA.

"Given that two accidents both involved newly delivered Boeing 737-8 planes and happened during take-off phase, they have some degree of similarity," the CAAC said. It added that it has a "zero tolerance" policy for safety risks.

Chinese airlines have a total of 96 737 MAX 8 jets in service, the state company regulator said on Weibo, including Air China, China Eastern Airlines, China Southern Airlines and Hainan Airlines.

Meanwhile, after initially insisting that its fleet of 737s would remain in the air, Ethiopian Airlines backtracked on Monday and grounded its 737s until further notice as an “extra safety precaution." The investigation into Sunday's crash is just getting started, while the probe into the Lion Air crash has yet to produce a conclusive finding.

Cayman Airlines, the British overseas carrier, said it would ground its 737s, though most of the major airlines around the world have not grounded their planes.

Here's a breakdown of 737 orders/deliveries showing which airlines are most reliant on the narrow-body jet (No. 1 is US-based Southwest), courtesy of Bloomberg:

Flight ET302, the Ethiopian Airlines flight that crashed on Sunday, was the second 737 MAX 8 to suddenly crash, killing everybody on board, within five months. In late October, the crew of a Lion Air flight reported technical problems with the plane before it suddenly dropped into the Java Sea off the coast of Indonesia. The two crashes were eerily similar, in that both occurred just minutes after taking off.

The 737 line is Boeing's cash cow, and the aerospace company has roughly 5,000 737s on back order - so making material redesigns for safety purposes could be hugely problematic for the company's production, and possibly lead to a flurry of cancelled orders. Already, 350 of the planes are in service around the world.