Maybe. I find it odd that I've never seen a dead one on the bridge. There are plenty of dead ones along the roads.
From the Missouri Department of Conservation:
“Armadillos can actually swim and float across bodies of water by gulping air into their intestines to make themselves more buoyant,” explained Shank. “They can even hold their breath for up to five minutes and float across bodies of water, or they can sink to the bottom like a rock and just walk across the bottom. It’s possible that their ability to swim has allowed them to expand to new areas and establish new territory.”
Nine-banded armadillos are tough, tenacious... and everywhere (but mainly on the side of the road).
mdc.mo.gov