An Amtrak train carrying 187 people collided with a freight train on Chicago's South Side, critically injuring five people and leaving dozens of others with less severe injuries, fire officials said Friday.

Live television footage showed emergency officials helping passengers and crew members walk off the Amtrak train's three double-decker passenger cars, which remained upright.

Several people were seen being carried away in stretchers.

Nine people were reported in serious condition and another 30 were treated for bumps and bruises, although Fire Commissioner Raymond Orozco expected that number to rise to about 50.

It was unclear how many of the six Amtrak workers aboard were hurt, but damage to the train was concentrated on its engine, where some of the workers were. Four people had to be extricated from front of the train, Orozco said.

The Amtrak train was coming from Grand Rapids, Mich., Amtrak spokesman Derrick James said. He said the National Transportation Safety Board was sending investigators to the scene.

With files from the Associated Press