An Alaska Airlines flight traveling from Portland, Oregon, to Ontario, California, had to make an emergency landing Friday night after a portion of the aircraft blew out mid-air.
This type of aircraft comes equipped with a rear emergency exit door, used mainly by international airlines, and has a seat configuration that allows for more passengers on the plane. Most U.S. airliners don't use that configuration and design the area to appear as a window from the inside of the aircraft.
Imagine the lawsuits if/when somebody dies due to an onboard fire/smoke.
I wouldn't take this seriously if it weren't for the fact that Boeing's propensity for up-charging for basic safety features didn't contribute to the crashes of two 737 Max 8.
It’s optional based on on the interior buildout of the plane. It depends on the number of seats and seating arrangement. When it’s not needed for an order, they bolt in a “plug” that fills the space where the door would have been.