Because Tyler's body has not been found, I have always entertained the small chance that he fell into a storm drain. Very unlikely but could explain the odd scenario. I have visualized storm drains as a big mess full of snag areas, debris, and standing water. I just looked up exploring storm drains on line and found some interesting videos.
One thing I notice in all cases, is that the storm drains remain clear, due to the circular design and the grates that are placed on the access points to prevent debris entering the drain, much to my surprise (and lack of awareness). Note, that you rarely hear of a storm drain blockage.
In the Easton area, the storm drain lines are likely small in diameter, and reasonably new and free of snags. This means that if someone fell in, they would likely eventually get swept to Alum Creek, about a mile away. I showed images in a previous post, that the storm drains in the mall area do drain into Alum Creek. However, I can't figure out where storm drains run in the Abbott Lab area.
So now I think that if Tyler fell into a storm drain, he would not remain there, and would have ended up in a body of water. In a densely populated area, it seems he body would have been found.