A man died Tuesday morning after his car plunged into a retention pond along Ogden Avenue near I-88 in Downers Grove.
Downers Grove police would not yet release the victim's name pending notification of his family.
Police said they received a call at 9:42 a.m. Tuesday with witness reports of a dark vehicle traveling at high speed along Authority Drive near the Illinois State Police District 15 headquarters. The car plunged into the pond and sank.
Downers Grove Fire Chief Jim Jackson said officials are unsure why the car left the road. There were no skid marks on the pavement or grass at the scene.
"Everything happened so fast, all people could tell us is that it was a dark vehicle traveling very fast and then into the pond," Jackson said.
Emergency crews arrived at 9:45 a.m., but some state troopers saw the accident from their headquarters and dove into the water to rescue the driver. They discovered the victim inside the car with the windows closed and broke one of the windows to reach him, officials said.
Rescue workers then began first aid, Jackson said, before the victim was taken to Advocate Good Samaritan Hospital in Downers Grove. The man was pronounced dead shortly after reaching the hospital.
Five Downers Grove rescue workers and three Illinois state troopers also were taken to Good Samaritan as a precaution for possible hypothermia from the cold water and to be treated for minor cuts and bruises, Jackson said. All were released Tuesday.
No other victims were found after a secondary search, officials said. More than 15 rescue agencies were on the scene at 11:45 a.m., with up to 75 people investigating the accident or trying to remove the car from the pond.
Gasoline was pooling at the top of the water where several divers worked, but the vehicle was not immediately visible from the surface. By 12:45 p.m., a badly-damaged black Ford Focus was pulled from the pond.
Because the accident happened after rush hour, traffic along Ogden Avenue was minimally affected, officials said.