Passenger Trains > Metra combining two trains together on BNSF line?

I saw something I've not seen before on the Metra BNSF line through Naperville today.   It was about 10:30am and an eastbound movement of two Metra trainsets combined together was seen with power for the movement coming from the unit that was in the middle of the train led by the cab car on the end.   It didn't sound like the unit on the end was running.  Does Metra regularly combine two trains together for one movement from Aurora to Chicago or was this an unusual movement?  

Sounds like the on one train failed and the used the second train to bring it home.

With the revised schedule, there aren’t any expresses at that time. Per the email I got from Metra, it was a mechanical failure with a rescue by the following train.

Posted from iPhone

Remember the time the Metra unit pushed one of the long distance Amtrak trains and pulled its own train?  I forget the details but it was neat.

Andy

I have seen a Amtrak Downeaster push a disable MBTA train from Bradford to Boston. Fortunately only one station required a double stop.