The modem/router was sitting directly on the carpet so it, at some point, got hot enough to ignite the small fibers of carpet. It essentially was a heat source on jute twine type fibers.
I found a storage unit that offers 4×6 sizes about 100 miles East of where I live for $39/month. Looks like a few month wait so I put myself on the list.
http://ageofdecadence.com