An Illinois man died and several members of his family remain hospitalized with carbon monoxide poisoning.  The carbon monoxide didn't come from the dead mans RV, but probably from a neibor, they were parked only 3 to 5 feet apart.  This shows how necessary it is to evaluate close parking while using generators and also the need to have a working CO Monitor and probably even a second CO Monitor, they aren't expensive.
http://www.courier-journal.com/apps/pbcs.dll/article?AID=/20080527/NEWS02/805270435