Title says it all. Ill start off with a 'fortunately' then the next person says an 'unfortunately.'
So, let's kick it off with an eg.
Fortunately, I won $100,000 on the lottery
Unfortunately, you got attacked by a fox, who rips up all your money and gets you hospitalised for a month.
Fortunately, your leg healed quicker than expected and you left the hospital.
Unfortunately, you realised you were late (duh) for your work session.
Carry on from above with a 'FORTUNATELY'.