Nov. 30 (Bloomberg) -- An Amtrak train collided with a freight train on Chicago's South Side this morning, injuring dozens of passengers and crew members, railroad and fire officials said.

The Amtrak train, No. 371, called the Pere Marquette, was on its way to Chicago's Union Station from Grand Rapids, Michigan, with 187 passengers and six crew members aboard when it struck a Norfolk Southern Corp. freight, according to an Amtrak statement.

The Amtrak locomotive derailed; the train's three cars remained on the rails, according to the statement. The trains collided near the intersection of 47th Street and Shields Avenue in an elevated area of railyards, a Chicago Fire Department spokesman said.

Fire department spokesman Kevin MacGregor said at least 47 people were hurt, eight of them seriously, and were taken to local hospitals for treatment. The count was likely to rise as the investigation continues, MacGregor said. At least four crew members suffered serious injuries, he said.

Earlier in the day the fire department told CNN that at least 100 people on the Amtrak train were hurt, including five crew members who were seriously injured.

The National Transportation Safety Board said in a statement that it's sending a team to Chicago this afternoon to investigate. Amtrak said service between points in Michigan and Chicago has been delayed.

The 20-car Norfolk Southern train was bound for Chicago from Elizabeth, New Jersey, and was carrying overseas shipping containers, said company spokesman Rudy Husband. There were two people on board the train, an engineer and a conductor, and neither was injured, Husband said.

``Our train was stopped waiting for a signal,'' Husband said in a telephone interview. ``It had just received a signal and was getting ready to move when it was struck from the rear by the Amtrak train.''

The section of track where the collision occurred is owned by Norfolk Southern and trains were being dispatched out of the company's office in Dearborn, Michigan, Husband said. The cause of the crash is under investigation, he said.

To contact the reporter on this story: Chris Dolmetsch in New York at cdolmetsch@bloomberg.net.

Last Updated: November 30, 2007 16:52 EST