Chicago ? A fatal train derailment this weekend might not have happened if the route had an automatic system that applies a train’s brakes when an engineer fails to do so, federal officials said Monday.

“I believe it (the braking system) would have prevented this type of accident,” said National Transportation Safety Board acting chairman Mark Rosenker.

Metra has automatic braking systems on three of its 11 routes serving Chicago and its suburbs, but commuter rail officials say it is expensive and not essential.

The double-decked commuter train carrying 185 passengers and four crew members was headed to Chicago from Joliet when its locomotive and five rail cars jumped the tracks about five miles south of downtown.

Metra riders returned to their morning commute Monday with the derailment in their minds.

“I was very concerned today getting on the train,” said Karen Freeman, 43, who commutes from the South Side to her court reporter job downtown on the same Metra line as the derailment. “But I’m confident they’ll get to the bottom of it.”