The train meltdown could not have come at a worse time - both for passengers, because it happened on the cusp of peak hour, and for Metro, because the Andrews government is believed to be on the verge of announcing it will hand Metro a seven-year contract extension.
For political reasons, it might be less likely to come out and announce this so soon after the system has let commuters down so badly.
Metro's automatic train control centre failed at 4pm, leaving the operator scrambling and at a loss to identify what caused the system failure.
With the system down, train controllers were staring at blank screens and literally did not know where in the network Melbourne's trains were, so all trains were brought to a halt for safety's sake.
Trains pulled up, either at platforms or in between stations, and sat there while staff in Metro's nerve centre raced to identify the problem and get the system back online.
It took well over an hour, leaving tens of thousands of commuters stranded on their way home from work.
Some trains were stuck in the City Loop while the system was down.
The system that failed is called TCMS and it cost $88 million to get up and running.
It was years in the making - first proposed as far back as 1999 and only switched on some 15 years later, in 2014, after interminable delays.
It was meant to improve the reliability of Melbourne's public transport system.
It's fair to say it mostly has until today, exposing yet again the fragility of Melbourne's 869-kilometre metropolitan rail network, where one problem in one room can spread to virtually every corner of the city.
One computer failure shouldn't shut down a city's rail system.
On Thursday evening, Metro still could not identify the cause of the problem.
There will be justifiable anger from commuters caught up in this mess, with fingers mostly pointed at Metro.
But it is government that is responsible for investing in public transport, while Metro is paid to run the system and sometimes act as a convenient shield at times like this.
Connex was thrown out of town because there were too many failures like this.
It's hard to imagine Metro being shown the door in the same fashion - who would the government turn to?
But the latest meltdown is more proof that Melbourne still has a long way to go to reach the kind of "world-class, turn up and go" system that is preached about.