CRYSTAL LAKE, Ill. » Authorities say four people are dead after a small plane crashed into a field near the northwestern Chicago suburb of Crystal Lake.

Federal Aviation Administration spokeswoman Elizabeth Isham (EYE’-sham) Cory says the crash happened about 10:30 a.m. Saturday in unincorporated McHenry County. All four people on board were killed.

Cory says the plane was operating by so-called "visual flight rules," meaning the pilot looked out the window to see where he was headed. The plane was not in touch with air traffic control. Conditions in the area have been overcast and rainy.

The aircraft was a Cirrus-SR22 registered to the Marion Flying Club in Marion, Ind.

Officials say they don’t yet know where the plane originated or where it was headed.

The National Transportation Safety Board is leading the investigation.