Has anyone participated in a "Walk for Life" event?

Faithroad

In a couple months my city is having a "Walk for Life" event to raise money for a cancer cure.  I was thinking of participating until I discovered it was a 24-hr. event.  24 hrs!!!!!!!  Sleeping over and walking through the night.  I guess that surprised me as many people are cancer survivors or fighting cancer.  I dont't feel like I can participate in something like that for 24 hrs.  I'm kind of bummed about it.  Yes I understand you take turns walking around a track you don't walk the whole 24 hours, but still, I can't see myself doing an overnighter.  Wish it was a one day event, even 12 hours would be ok, just not overnight.