Last week I had my bike fit. They told me to ride a lot and to get use to my new position. I did and my rear wheel fell off. The Bike fitter's mechanic forgotten to tighten my Skewers since he swapped them to fit in their bike trainer.
Good thing I was not going more than 20mph at that time.
I tighten it and shake it off. And then my handle bars start shaking... crap... they did not tighten the stem and fork that good.
Learned my lesson... I stop and check every little thing.
From now on... I am double checking everything every time I take off, specially when somebody touch my bike.