An unidentified person found dead inside the Thornton Composite Reservoir fell to their death in an apparent suicide, an autopsy on Thursday showed.
The body was discovered Wednesday morning inside the 300-ft-deep reservoir in the 17200 block of State Street in Thornton and later pronounced dead at the scene, officials said.
Local authorities used a drone to help locate the body, which was moved from the site Wednesday evening, according to Alison Fore, a spokeswoman for the Metropolitan Water Reclamation District of Greater Chicago, which operates the reservoir. She had no other details.
An autopsy determined that the still-unidentified person died as a result of multiple blunt force injuries caused by the fall and that the death was ruled a suicide, according to the Cook County medical examiner’s office.
A part of the long-term Deep Tunnel stormwater project, the composite reservoir significantly reduces flooding and the backflow of untreated sewage into Lake Michigan by storing combined sewer overflow during floods before release to the Calumet wastewater treatment plant, according to the U.S. Army Corp of Engineers. The reservoir is also the largest combined sewer overflow facility in the world, according to Wastewater Digest.