GO Transit trains, UP Express slowly resume service after CN system outage

A network-wide system failure at CN Rail that saw afternoon rush-hour travel for commuters across the Greater Toronto Area thrown into chaos Tuesday has been resolved.

The outage halted all GO Transit trains, as well as a rail link to Toronto's main airport.

CN Rail said late Tuesday afternoon that it was experiencing "an internet connectivity and electronic data interchange issue." 

"While there is no indication of a cybersecurity issue, the cause of the outage is currently under investigation," it wrote.