Bootstrap grid system for thumbnail images

Hello,
I’m working on my first independent project (tribute page). I’m trying to get three thumbnail images to line up using bootstraps grid system. When I put all the individual images nested inside a <div class="row"> the first image sits in a row by itself and the other two line up next to each-other in a row. If I remove the <div class="row"> then its works. However this is not what all the instructions say to do. What am I missing here?

See the Pen FCC Project Tribute Page by Jay (@ajwillis) on CodePen.

Thanks! That worked.