Whiteside County Sheriff Roger Schipper says the four-seater helicopter crashed nose-first into the ground about a half-mile north of Coleta.
Schipper says the copter took off this morning from Wisconsin and was heading south when the crash happened at about 8:30 a-m. He says two adults and a child were killed.
Witnesses say the helicopter appeared to be having engine problems.
Investigators from the National Transportation Safety Board and the Federal Aviation Administration are en route to the scene.
Coleta is a small town north of Sterling near the Whiteside-Carroll County line.