con-pilot
Too true, just how many have gone under since?
Pan Am
. . .
OK, let's start with the start ups list: 
Jet Blue
? ? ?
Companies are born and start to grow. Some don't make it past childhood and some live for while and do OK but then marry into another company.
Some companies live a loooooong time and then, they are so old and set in their ways, they find that they have come to the end of their time. So, someone buys the house and furniture that they lived in and manages to reuse parts of it again.
In Europe, we have lost Swiss Air and SABENA and now Alitalia is about to lose it's house.
Companies are just like the people who start and run them. They grow old and die and those that have lived in and with them grieve.
Around the world, we are entering a period of grieving for many kinds of company, not just airlines. Nope, I don't like it either, but we have not learnt from earlier cycles of Boom-and-Bust and now we are going Bust.