I've gone back and re read the posts. Thank you SubRosa for the suggestion. My tank will now get a 50% water change every week.
What some of you don't quite understand is that I've always done 100% water changes (leaving a bit at the bottom) and there were no issues up until now. The fish were only in the bowl for about 15-20 minutes...could there have been too much ammonia in the water? Or not enough oxygen?
It is possible that something changed in your tap water. Mine doesn't stay consistent here, and at times, municipalities do maintennace on the systems and generally shock them with different additives. My tap ammonia is currently running at 1 ppm.