Chicago, Illinois - Thieves stole around $100,000 in equipment from Soldier Field, the home of the Chicago Bears, overnight on Wednesday, stadium officials said.

The "substantial theft of equipment" targeted mowers and John Deere Gators that belong to a subcontractor and were being stored at the Waldron Deck parking lot, Soldier Field spokesperson Luca Serra said.

The equipment was tucked away behind a trailer, wedged between the trailer and a fence, he said.

"They tore out the fence overnight," Serra said, "and walked away with $100,000 in equipment."

The equipment did not belong to the NFL team, the stadium spokesperson clarified.

The Bears also confirmed none of their property was stolen from Soldier Field.

The equipment was insured, and the stadium and subcontractor are working with police to identify the thieves and determine what steps can be taken to better secure the facility, Serra said.

The theft from the parking lot near the Lakefront Trail and surrounded by city parkland was not captured by surveillance cameras, he said. Such a major theft hasn't happened at the stadium before, he added.

"Unfortunately, you can't put a security guard by everything," Serra said. "We hope that this is just a one-off."

The Chicago Police Department said detectives are investigating the theft. The crime was committed by an unknown number of offenders and no one has been arrested, police said.