• A Boeing 737 Max 8 operated by Ethiopian Airlines was the second such plane to crash in five months on Sunday.
• No cause has been determined, but its similarities to the Lion Air crash in October have caused several major countries to ban the airplane.
• Boeing says it will soon roll out software updates to fix a problem with how the plane flies.
• Several US senators have called on the federal government to also ban the plane.
• Boeing's stock price, as well as shares of related companies, all took a hit this week because of the crash.

Ethiopian Airlines' deadly crash on Sunday was the second disaster involving a Boeing 737 Max 8 aircraft in the last five months.

The apparent similarities to the crash of Lion Air in October has sparked an outcry from US lawmakers as other countries - including China, Britain, Australia, and more - ground the plane pending further investigation.

Here's what we know so far about Sunday's crash and any similarities to the Lion Air disaster so far:

All of the 157 people on board were killed

When the Ethiopian Airlines plane plunged to the ground shortly after takeoff from Addis Ababa en route to Nairobi, all 149 passengers and eight crew were killed.

The airline's CEO told journalists that those involved hailed largely from African countries, as well as 18 Canadians, eight Americans, and others from a handful of European countries.

Here's the full list of nationalities of people killed on board.

One passenger, who accidentally missed the crashed flight by two minutes said in a Facebook post that he was "grateful to be alive," despite being angry previously that no staff could help him find his gate.

Boeing's response

Boeing, the US-based manufacturer of the 737 Max 8 involved in the crash, has rolled out a software update in response to the two crashes, it said Tuesday.

At the heart of the controversy surrounding the 737 MAX is MCAS or the Maneuvering Characteristics Augmentation system. To fit the MAX's larger, more fuel-efficient engines, Boeing had to redesign the way it mounts engines on the 737.

This change disrupted the plane's center of gravity and caused the MAX to have a tendency to tip its nose upward during flight, increasing the likelihood of a stall. MCAS is designed to automatically counteract that tendency and point the nose of the plane downward.

Unfortunately, initial reports from the Lion Air investigation indicate that a faulty sensor reading may have triggered MCAS shortly after the flight took off.

Here's the company's full statement:

For the past several months and in the aftermath of Lion Air Flight 610, Boeing has been developing a flight control software enhancement for the 737 MAX, designed to make an already safe aircraft even safer. This includes updates to the Maneuvering Characteristics Augmentation System (MCAS) flight control law, pilot displays, operation manuals, and crew training. The enhanced flight control law incorporates angle of attack (AOA) inputs, limits stabilizer trim commands in response to an erroneous angle of attack reading, and provides a limit to the stabilizer command in order to retain elevator authority.

Still, Boeing's statement has done little to calm fears of global air travel regulators around the world.

Major countries have banned the plane

On Tuesday, a huge swath of European nations, including Germany, France, the UK, and Italy all banned the 737 Max from their airspace until a thorough investigation can be completed.

The US' air safety regulator on Monday said the plane was still safe to fly, but demanded a few changes to the plane for Boeing to make. For now, the Federal Aviation Administration does not appear to be following the rest of the world in grounding the plane.

"External reports are drawing similarities between this accident and the Lion Air Flight 610 accident on October 29, 2018," the FAA said. "However, this investigation has just begun and to date we have not been provided data to draw any conclusions or take any actions"

A handful of American lawmakers, including at least three senators and a representative, have called on the FAA to ground the plane.

The crisis could have a big impact on Boeing's business

Shares of Chicago-based Boeing have fallen more than 13% since the crash on Sunday, as some airlines have reportedly asked to delay the delivery of the 737 Max 8 aircraft they have on order.

The company's order book - aircraft that airlines around the world have agreed to purchase - is overwhelmingly comprised of the plane in question.

"We are not surprised by the negative stock reaction, as the 737 represents the strongest backlog, free cash flow (FCF and potential upside from further rate increases," Ken Hubert, an analyst at Canaccord Tenuity, said in a note to clients on Monday.

"We view the risk as less about near term expenses, but the full year 737 delivery estimates for BA could be impacted. We do not expect BA to slow the 737 pull from suppliers. Moreover, the larger risk is the reputational concern for BA," he continued.

Boeing's plunge also dragged down the Dow Jones industrial average, of which it comprises a large percentage.

Airlines could take a hit too

Southwest is the US airline most exposed to the 737 Max 8, according to calculations by Joseph Denardi, an analyst at Stifel.

The 737 MAX comprised 2.2 of Southwest's scheduled available seat miles (ASM) for March, and is projected to grow to 2.6% by June. The airline reportedly said Tuesday that it's "working with Customers individually who wish to rebook their flight to another aircraft type."

Around the world, 59 airlines operate 387 of the 737 Max 8 and 9, the FAA said. In the US, there are 74 of the airplanes registered.

Airline stocks and other related aerospace companies stock prices were also taking a hit this week, Markets Insider reports.

What comes next

The "black box" flight data recorder for Sunday's crash was found Monday, Ethiopian Airlines said in a statement. Investigators from the country, assisted by the US' National Transportation Safety Board, have yet to reach a final conclusion.

Benjamin Zhang contributed to this report.

More about the Boeing 737 MAX 8 and the Ethiopian Airlines disaster:

• Seven airlines and 5 countries have grounded the Boeing 737 Max 8 after a 2nd crash involving the plane killed 157 people - here's who's taken action so far
• There's a significant difference between the Ethiopian Airlines and Lion Air plane crashes, which both involved the Boeing 737 Max 8
• These are the victims of the Boeing 737 Max 8 crash in Ethiopia
• FAA says Boeing 737 Max 8, the plane that's crashed twice in 5 months, is still safe to fly
• Southwest has the largest exposure of all US airlines to Boeing's 737 Max
• The black box from the crashed Ethiopian Airlines flight has been found
• The family of Ethiopian Airlines Flight 302 captain speaks out after crash that killed 157 people
• A Georgetown University law student who reportedly expressed a fear of flying is among the 157 dead in the Ethiopian Airlines crash
• An Ethiopian Airlines passenger said he missed the crashed flight by 2 minutes: 'I'm grateful to be alive'
• People of 35 different nationalities were killed in the Ethiopian Airlines crash, including 8 Americans

Get the latest Boeing stock price here.