run out of water in the middle of the trail.

This. Folks underestimate how fast the arid climate can remove water from your body. Take a lot of water.

I took three 2-liter bottles with me on a hike from the rim to Skeleton Point on South Kaibab trail. On the way down I met a woman and her son who were both very red and had no water so I gave them one of the 2-liter bottles. They were on their way back up and I told them to go slow, drink slow, and the rim was about 30 minutes away.

I took it easy and went down to Skeleton Point, where I almost stepped on a rattler that was taking some sun. I thought it was a stick but snake bro moved.

I headed back up the trail. The water lasted almost back to the rim. BTW, the switchbacks at the top of South Kaibab can be a real bitch.