What caused the Boeing plane issue and what does it mean for the rest of the fleet?

Boeing is back in the spotlight after a door panel blew out of a plane, and all 737 Max 9s with similar door plugs have been grounded

• Boeing shares fall after door panel blown out of plane mid-flight

An incident on an Alaskan Airlines flight where part of the fuselage tore away has again put the spotlight on Boeing's newest and top-selling model, the 737 Max. Here we look at what happened and what it might mean for Boeing and its 737 Max.