CHICAGO – The derailment of two Metra commuter trains along the same line were accidents and just a bizarre coincidence likely caused by track problems, authorities said Wednesday.

The FBI had looked into Tuesday night’s derailments, which happened within 90 minutes of each other, to make sure there was no connection to suspected sabotage along the same line last week.

“We can say with absolute certainty there was no foul play involved, no tampering to any extent,” said Metra spokesman Judy Pardonnet. “It was a strange situation where two trains derailed on two separate tracks at the same location.”

Both trains on the South Branch of the Metra Electric District were moving slowly near a station, on different tracks, when the derailments occurred. No one was injured, and the cars stayed upright.

The derailments occurred near a busy crossing, and Metra officials determined that heavy vehicular and train traffic had caused a slight separation between the tracks, Pardonnet said.

The northbound tracks had been inspected Sunday and the southbound tracks Tuesday morning, but the tracks could have shifted enough in that span to cause a railcar’s wheel to slip off the rails and into the track bed, Pardonnet said.

The Metra spokeswoman said such minor derailments do happen, but Tuesday night’s drew more attention than usual because there were two instances and because of recent worries on the line.

Last week, Metra discovered more than two dozen spikes – used to hold down metal plates that bind the rails to wooden ties – had been removed from tracks along a different stretch of the same line, but the sabotage caused no mishaps.

“The removal of spikes, in our opinion, was an intentional act,” said FBI spokesman Ross Rice. “The derailment of the two trains was accidental.”

A federal investigation into the removal of the spikes continues, Rice said. There have been no arrests made or charges filed. The FBI is offering a $50,000 reward for information.

As for the derailments, Pardonnet said a special railcar that examines track alignment will be used in the next week, but that Metra officials were confident in corrections they made to the tracks on Wednesday morning.

Metra also examined three other crossings similar to the one where the derailments occurred and found no problems.

“It was a very isolated incident,” Pardonnet said. “It’s unfortunate because passengers are concerned about it, we are concerned about it – especially after last week. Everybody’s ultra sensitive.”

Commuters on Wednesday said the two derailments, plus the suspected sabotage, left them concerned, but not deterred.

“I know some people are nervous about it but it’s in God’s hands,” Beverly Manuel said after her morning trip into the city on the Electric District Line.

Manuel, 52, called the Metra her best option for getting from Chicago Heights to her job as an office services manager.

Kiesha Miller, who commutes 40 minutes each way from Oak Forest to her advertising job in Chicago, agreed. “Any time something like that happens, you definitely want to take precautions and stuff. But then again, it’s my only means of transportation right now,” she said.