Undated (AP) _ Illinois' strongest earthquake in 19 years shook residents of 16 states from Kansas to South Carolina and parts of Canada, breaking windows, tumbling chimneys and causing buildings to sway up to 700 miles away.

Wednesday's temblor, registering 5.0 on the Richter scale, cracked a bell tower, triggered an alarm at a Minnesota nuclear plant and cut telephone service in three Illinois counties, but only minor damage and one minor injury were reported.

''It felt like somebody with big shoes was walking overhead, but nobody lives overhead - we're on the fourth floor,'' said Richard Horwitz of Chicago. ''Our parakeet was chattering away, and it just stopped.''

The quake, at 6:49 p.m. CDT, was centered near Lawrenceville, Ill., 55 miles north of Evansville, Ind., the National Earthquake Information Center in Golden, Colo., said. Shaking was felt from 10 seconds to nearly a minute.

Hundreds of students ran screaming from a building at a vocational college in Indianapolis, and about 70 people were evacuated from a swaying, 12-story apartment house in Columbia, S.C., 700 miles from the quake center.

''I thought I was going to die and I thought, 'Well, I'm in church and I can't think of a better place to die,''' said Betty Meyer, a Bible school instructor at First Christian Church in Bridgeport, Ill., where the quake cracked the bell tower.

John Larson, a Lawrence County, Ill., sheriff's dispatcher, said there were several reports of broken windows and other minor damage. An 18-month-old girl received stitches after the quake forced a bunk bed to fall on her head.

Police dispatcher David Hoffee in Olney, Ill., said there were reports of broken windows, fallen chimneys and a roof collapse at a funeral home.

Three nuclear power plants in Illinois declared ''unusual events'' after the earthquake, contacting state and federal regulators, said spokesman Jan Strasma of the Nuclear Regulatory Commission in Glen Ellyn today. The plants were Dresden, near Morris, Quad Cities, at Cordova, and Clinton, Strasma said.

There were no reports of damage or disruption of service from any Illinois plant, and the unusual event declaration was lifted from all of them, he said.

At the Prairie Island nuclear plant near Red Wing, Minn., the quake triggered a seismic alarm, but no damage was immediately detected, said Sam Macalus, spokesman for Northern States Power Co.

''We've gotten calls from listeners about broken glasses, refrigerators shaking, pictures falling off walls,'' said Dave McLean, a reporter for WTTL in Madisonville, Ky. ''One lady called and said she was scared so bad because her grandfather clock was chiming and it wasn't time for it.''

State police in Battle Creek, Mich., reported ''thousands of calls, minor damage, but no injuries.''

The quake was felt in Kansas, Missouri, Minnesota, Iowa, Illinois, Indiana, Ohio, Michigan, Wisconsin, Kentucky, Tennessee, West Virginia, Virginia, Pennsylvania, the Carolinas, and several cities in Ontario.

Members of Chicago's Streets and Sanitation Department were in a meeting hen the quake hit. ''I thought the man next to me was jiggling the table,'' said Kirsten Svare, department public information officer.

''I was lying on the sofa and all of a sudden it started shaking,'' said Mrs. Sam May of Lebanon, Ky. ''I thought I must have a ghost in the house.''

The quake was the strongest in that area since a magnitude 5.3 tremor near Norris City, on Nov. 9, 1968, said Don Finley, public affairs officer for the U.S. Geological Survey in Washington, D.C.

''I think this will serve as a reminder that we do live in an area that can have earthquakes,'' said Gregg Durham of the Illinois Emergency Services and Disaster Agency. ''A lot of people had their wits scared out of them.''

''A 5 in the East is substantial. A 5 out West is nothing,'' said Charles J. Ritter, a geology professor at the University of Dayton, Ohio. ''The shock waves will travel through the uniform rock, like we have in the East, much farther.''

Russ Needham, a geophysicist in Golden, said scientists had not pinned down the source of the tremor, but it was north of the New Madrid fault, the site of an 1811 quake so powerful it changed the flow of the Mississippi River.

Near Erie, Pa., Catherine Shaw, 76, and her husband, John, said they were watching television when the quake hit, and their chairs started rocking. ''We don't have rocking chairs,'' Mrs. Shaw said.

At St. Paul-Ramsey Medical Center in Minnesota, a patient in traction saw apparatus on his bed shaking, said nursing assistant Anita Sauerwein. ''He said he thought it must be the drugs and he rolled over and went back to sleep.''

Detroit rock station WRIF-FM was playing ''Shakedown'' by Bob Seger when the quake hit. ''I felt my chair kind of shaking and the microphone was sort of wobbling,'' said disc jockey Steve Kostan. ''I said, 'Can this song really be that good?'''

It also shook the rooftop press box at Detroit's Tiger Stadium for nearly a minute during the first inning of the game between the Tigers and the Milwaukee Brewers, but players said they didn't feel it.

At Prisoners Hospital in Plainfield, Ind., some patients' beds slid away from the walls and the prisoners were ''scared like the devil,'' said James Bell Yager, executive director of the National Prisoners Rights Union.

The Richter scale is a measure of ground motion as recorded on seismographs. An earthquake of 4 on the scale can cause moderate damage, 5 considerable damage, 6 severe damage.

On July 27, 1980, a ''very rare'' quake registering 5.1 hit northern Kentucky and was felt for 300 miles in all directions, shaking people in 14 states and southern Canada. No injuries were reported.

06-11-87 1253EDT