OAK CREEK - The U.S. Coast Guard in Milwaukee suspended the search for a possible missing aircraft in Lake Michigan just before 6 p.m. Wednesday.

The search will not resume unless more definitive information is received, Petty Officer 1st Class Vance Cunningham said Wednesday night.

The Milwaukee County Sheriff's Department received a 911 emergency call at about 1:40 p.m. Wednesday for a plane going into the water about three miles off shore from Oak Creek, said Kim Brooks, a Sheriff's Department spokeswoman.

The 911 call came from an employee at the We Energies Oak Creek power plant.

Construction workers on an elevated building made the call, said Lt. Kristie Cabanting of the Milwaukee Coast Guard office. The power plant is approximately four miles from Wind Point and near the borders between Racine and Milwaukee counties and Oak Creek and Caledonia border.

Searches "lead us to the possibility that it's maybe not an airplane crash, but we are searching until we exhaust all possibilities and we determine there is no distress on the lake," Cabanting said at a 4 p.m. Wednesday press conference in Milwaukee.

There was no confirmation of a plane down and no reports of any missing planes, Cabanting said. A debris field on Lake Michigan was reportedly spotted by a Coast Guard helicopter, but the debris was later confirmed to be a recreational boat and a buoy, Cabanting said.

No plane from Racine's Batten International Airport was reported missing, said Larry Runge, airport line technician.

An aircraft matching the description of what the eyewitness possibly saw fit the description of a plane that took off from a Kenosha Airport Wednesday afternoon. However, the aircraft's pilot was located. Coast Guard public affairs assistant Julie Harkinson said the pilot and plane are safe.

Runge said officials from General Mitchell International Airport in Milwaukee called Batten to see if a plane had taken off from their field.

Officials at Mitchell believe the reported missing plane was either a biplane or ultralight plane, according to Runge. An ultralight plane is a homemade aircraft that could have taken off from a backyard or field. A biplane is a small two-wing, two-person aircraft, Runge said.

A caller identifying himself as a security worker at the power plant told WTMJ (620 AM) on Wednesday afternoon that he saw an ultralight operating near the plant.

Two Coast Guard boats were in the water conducting the search Wednesday. A 25-foot small response boat and 41-foot utility boat were immediately dispatched, according to the Coast Guard.

A Coast Guard auxiliary plane also responded, as well as crews from several local agencies, including the Coast Guard in Waukegan, Ill. and police and fire rescue teams from Milwaukee, South Milwaukee and Oak Creek. An incident command post was set up in Oak Creek, Cabanting said.

The Federal Aviation Administration in Milwaukee is also investigating and will have an initial report available on the incident Thursday, said FAA spokesman Bob Moore.

Journal Times reporters Paul Sloth, Lindsay Fiori and Pete Wicklund contributed to this report.