RedactedNarrative: On May 28, 2011 at approximately 9:00 AM operator, along with his wife, and two others left Kenosha Wisconsin enroute to the Illinois River aboard Vessel 1.  At approximately 3:00 PM Vessel 1''s crew went through the locks on the Chicago River near DuSable Harbor.  During this time occupant1 entered the engine compartment to tighten the propeller shafts and became overwhelmed with carbon monoxide.  occupant1 exited the engine compartment and collapsed on the deck.  occupant1 was conscious, but could not move.  two others, who were in the cabin, came out on deck to render assistance to occupant1 .  operator was operating Vessel 1, operator opened all the windows and doors onboard, then guided Vessel 1 toward a small marina and moored Vessel 1 on the south side of the river facing west.  operator then called 911 and requested ambulance service.  wife complained of feeling ill due to carbon monoxide poisoning.  occupant2 suffered a stroke a year ago and, but did not feel any effects from carbon monoxide poisoning.
  
  Chicago Police Marine Unit responded to the scene along with Chicago Fire Department EMS.  EMS transported victim to Northwestern Memorial Hospital for Oxygen Treatment.  occupant2 was treated as a precaution due to suffering a stroke prior to the accident.  All three were released approximately three hours later.
  
  All injured parties, after release from the hospital, have not suffered any illness due to the exposure.
NameOfBodyOfWater: Chicago River
NearestCityTown: Chicago                       