ST. CHARLES, Ill. (CBS) — Authorities in Kane County are awaiting toxicology reports to determine how a circus worker died at the county fairgrounds this past weekend.

An autopsy was conducted by Kane County Coroner’s investigators on Monday, but the autopsy proved inconclusive pending the toxicology tests, according to St. Charles police.

Police and fire crews were called to the fairgrounds at about 3:50 a.m. Saturday for a report that a 22-year-old circus employee was found unconscious in his trailer. Casey Dale Walker, of the 400 block of Masterview Drive, Etowah, N.C., was found slumped over his dresser in the bedroom, police said.

Walker’s roommates carried him outside of the trailer and began CPR. The first officer to arrive on the scene also began performing CPR, police said.

Paramedics transported Walker to Delnor Hospital in Geneva for treatment. Walker was pronounced dead at the hospital at 5 a.m.

Witnesses told police they had noticed a bump on Walker’s forehead earlier in the night. A witness also advised officers that she saw a metal pipe accidentally fall on Walker’s forehead several hours before he was found in his trailer.

Police said Walker was drinking alcohol with his fellow Piccadilly Circus workers earlier that night. There were no signs of a struggle around the trailer.

None of the news reports on Walker’s death have indicated whether he was a circus performer, or if he worked in the circus in some other capacity.

Not to be confused with the iconic public square London of the same name, the big top Piccadilly Circus is based in Sarasota, Fla. – a city known as the historic winter home of circus magnate John Ringling. The production bills itself as a family-friendly event with acrobats, elephant and camel acts and other traditional circus attractions.

The circus was set to perform at the Kane County Fair from Wednesday through Sunday, and is to appear in Melrose Park for four days beginning Tuesday.

The Aurora Beacon-News contributed to this report, via the Sun-Times Media Wire.

(Source: Sun-Times Media Wire © Chicago Sun-Times 2012. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)