Snow
No idea if it was snow related, but this is exactly the reason I switch my KLM flights to Newcastle during the worst of winter. I have two long hauls in the next 3 weeks, both with KLM and one will be the 6am out. I just won't risk an MME snow delay to put more pressure on the working week.
I know it isn't exactly what is needed when we should be supporting the airport, but I don't take the chance.
On a 6am out some weeks back, we got held for nearly an hour because the fireman had slept in....nearly missed my connection!