For some, this is the quintessential sound of the summer.

While you may not be a fan of the heart pumping, adrenaline boosting feeling of a rollercoaster's

twists and turns, for others, it's the best part of the warmer months or even a core memory.

Hey there, this is Lester from Colorado.

I remember my first greatest memories as a young boy was riding on the vortex coaster.

My hometown here in Penselton.

We would ride the coaster and just...

I'm sorry, I'm getting a little choked up here.

This is Ruth from Annapolis.

My mother was a rollercoaster freak.

She loved them so much and her biggest joy was when I turned seven, I am now 83.

At seven, I was tall enough to go on the rollercoaster with her and that made her so happy

because before my father wouldn't go and she had to go by herself.

So that's my comment about rollercoasters and they've been a lifetime joy.

Lester, Ruth, thanks for those messages.

Even though rollercoasters are a fond memory for many of you, recently two rollercoaster

incidents hit the headlines.

Over the 4th of July holiday, coaster riders at a Wisconsin festival were stuck upside

down for about three hours after a mechanical failure.

And last weekend, a North Carolina man spotted a crack in a rollercoaster beam after his

family had just been on the ride.

So how safe are rollercoasters?

...