Will County authorities confirm the accident happened around 9 a.m. at a private crossing near Elwood, about 40 miles south of Chicago.
The Statehouse train from St. Louis to Chicago was carrying 103 passengers when the crash occurred, said Amtrak spokeswoman Debbie Hare.
Will County Sheriff's Lt. Marty Shifflet said the train stayed on track and showed little damage, while the truck was "extremely twisted."
"It was demolished and on fire," Shifflet said.
Officials did not immediately release the names of those injured in the truck.
The gravel crossing at the accident site had no flashing lights or gates, Shifflet said.
The train stopped at the site but was expected to continue into Chicago later Wednesday, Hare said.
The accident site is about 12 miles south of Joliet along Illinois Route 53.