China has ordered all domestic carriers to ground their Boeing 737 MAX 8s after one of the jets seemingly dropped from the sky southeast of Addis Ababa just six minutes after taking off on Sunday. That accident - which killed all 157 people on board - was the second involving one of the jets in five months, and has led to speculation that Boeing might order all of the jets to be grounded pending further inspection.

Chinese media outlet Caijing was the first to report the decision, citing sources within China's domestic airline industry. Thee 737 MAX, the fourth generation of Boeing's narrow-body 737 line, was first flown in 2016, making the string of crashes - two in five months - unprecedented and, according to some analysts, extremely suspect.

China airline officials have suspended operations for the Boeing 737 Max aircraft: report pic.twitter.com/93QLjL4FrW

— Global Times (@globaltimesnews) March 10, 2019

The first crash occurred in late October when a 737 MAX operated by Lion Air crashed into the Java Sea, killing the nearly 200 people on board. Before the crash, the crew had reported unusual activity in the jet, including the nose of the plane unexpectedly tipping lower, which was blamed on a faulty data system. That crash is still under investigation.

Though its possible the two accidents could be a coincidence, the fact that they both involved brand new planes is particularly concerning. Yet, airlines have been reluctant to ground flights without a cue from Boeing, or some more evidence unearthed by investigators that the crashes could have been the result of some wider flaw in the plane's design. Ethiopian Airlines, which operated the ill-fated flight ET302 destined for Nairobi, has the best safety record of any carrier in Africa, and its CEO said at a Sunday press conference that its 737 MAXs would remain airborn.

Update: There are currently hundreds of Boeing #737MAX jets airborne across the globe right now, including an @FlyEthiopian Airlines one. pic.twitter.com/scqq1bt9wW

— Alex Macheras (@AlexInAir) March 10, 2019

As aviation analyst Alex Macheras pointed out during a series of appearances on cable news shows, the fact that two Boeing 737s have crashed in such a short period is truly unprecedented, and it is surprising that Boeing hasn't already ordered all of the planes to be grounded pending a review.

LIVE: “It is unprecedented that another Boeing #737MAX is involved in a fatal accident in the space of just five months” #ET302 pic.twitter.com/WwsEi2MbQS

— Alex Macheras (@AlexInAir) March 10, 2019

As airlines slowly wake up to the fact that the lives of hundreds of passengers may be at risk, they might opt to ground the planes on their own,.

Already, futures have dipped on the news out of China. If the groundings become a trend, Dow component Boeing could drag down the broader market on Monday.