Assistant Chief Rich Oney (left) and Captain Dave Lewis of the St. Charles Fire Department talk at the scene of a fire Wednesday. (Joel Currier / P-D)

ST. CHARLES - Police and firefighters are investigating a fire at a home business that started early Wednesday morning on McDonough Street just off South Fifth Street.

Captain Dan Casey of the St. Charles Fire Department said the fire began about 6:45 a.m. in the basement two-story home, which houses Jordon Properties, a real estate business.

No one was home at the time. Firefighters put out the fire in about 20 to 30 minutes.

The fire gutted the house, causing an estimated $75,000 in smoke and heat damage, Casey said. The fire started near a computer in the basement but authorities had not determined a cause.

St. Charles police were taking photographs and using an arson dog to investigate the property Wednesday morning.

Firefighters initially had difficulty finding the property owner who lives there, but contacted him later this morning, Casey said.

Casey said it is not likely a suspicious fire.