Firefighters extinguish a brush fire in the 9700 block of Route 176 near Crystal Lake on Thursday. | Photo: Alex Vucha / Lake and McHenry County Scanner.

The sheriff’s office said that authorities located a missing person nearby a large brush fire Thursday near Crystal Lake, but the two incidents are believed to be unrelated.

A McHenry County sheriff’s deputy on patrol was flagged down by a concerned citizen around 3:50 p.m. Thursday, according to McHenry County Sheriff Spokeswoman Sgt. Aimee Knop.

Knop said that the citizen notified the sheriff’s deputy of a brush fire in a marshland in the 9700 block of Route 176 in unincorporated Crystal Lake.

The deputy requested the Crystal Lake Fire Rescue District to respond to the scene and began assessing the fire.

Firefighters extinguish a brush fire in the 9700 block of Route 176 near Crystal Lake on Thursday. | Photo: Alex Vucha / Lake and McHenry County Scanner.

Crystal Lake Fire Chief Paul DeRaedt said firefighters arrived and found approximately 300 yards by 200 yards of brush burning.

Due to high wind gusts and swampy ground conditions, additional resources through the Mutual Aid Box Alarm System (MABAS) were requested.

There was no damage to any structures and no one was injured in the blaze, DeRaedt said.

Firefighters from Algonquin-Lake in the Hills, Barrington-Countryside, Cary, Fox River Grove, Huntley, Lake Zurich, McHenry, Nunda-Rural, Richmond, West Dundee, Wonder Lake and Woodstock assisted.

Paramedics respond to evaluate a missing person that was located in the 9700 block of Route 176 near Crystal Lake on Thursday. | Photo: Alex Vucha / Lake and McHenry County Scanner.

As crews battled the fire, a separate incident was reported involving a missing adult female in the same area, Knop said.

Firefighters assisted law enforcement in the search and over an hour later the woman was located in the vicinity by the Crystal Lake Police Department.

She was transported to the hospital for an evaluation. “There is no evidence at this time that the two incidents are related,” Knop said.

The cause of the fire remains under investigation by the McHenry County Sheriff’s Office and Crystal Lake Fire Rescue District.