Parts of England and Wales experienced a major power outage during Friday night's hours leaving commuters stranded and officials demanding answers.
The nine-hour disturbance left commuters stuck on trains and others trapped in gridlock traffic due to non-working traffic, according to The Guardian.
The rail services were still not restored Saturday morning, although power was restored to around 1 million customers, the newspaper reports.
A National Grid spokeswoman told the BBC 4 radio program that the interruption was an "incredibly rare event."
"The main cause of yesterday's problem was not with our system, but was a rare and unusual event, the almost simultaneous loss of two large generators, one gas and one sea wind, at 1
Nick King, a Network Rail spokesman who manages most of Britain's railways, told the newspaper that a "major system failure" had hit the network as a result of the power outage, leading to delays continuing into Saturday.
"Unfortunately, a particular fleet of trains suffered a major system failure as a result of the National Grid error," the spokesman said. "Many of these trains failed to start on their own and had to be joined by an engineer, which caused significant disruption to parts of the network."
"We worked flat with colleagues from the train operator and British transport police to safely get passengers off of affected trains," he added.