Sarah, Im so sorry for the loss of your little suggie. Thank you so much for coming here and posting this warning. As heart-wrenching as this is, your post may very well save another suggies life.
Everyone please check all of your fabric suggie items for loose threads before putting them in the suggie cage. Check them everytime they are washed. Clip off any loose threads anytime you see one. Also be very careful about using any kind of ribbon, string or rope.