G train riders had an unpleasant day thanks to a derailment Thursday night that caused service interruptions for much of Friday. Turns out the incident was caused by a crumbled, deteriorating wall near the Hoyt-Schermerhorn station, and the MTA says it's City Hall's fault for not giving the agency enough money.

MTA Chairman Thomas Prendergast blasted the de Blasio administration yesterday for failing to invest $3.2 billion into the transit system's Capital Program. Per a statement:

Unfortunately, the regional consensus that has rebuilt the MTA is fraying. The MTA’s proposed 2015-19 Capital Program would invest $26.8 billion to renew, enhance and expand the transit network. We asked the State of New York to invest $8.3 billion, and Governor Cuomo agreed. But when we asked the City of New York to invest $3.2 billion, they offered only $657 million. The City’s contribution has fallen far short of the rate of inflation, much less real support for the $800 billion worth of MTA assets within the five boroughs.

Our 2015-19 Capital Program allocates $927.5 million for repairing and rebuilding subway line structures, including bench walls such as the one involved in last night’s derailment. That’s more than double the $434.5 million in the prior program. But the MTA is barred by law from spending a single dollar on new capital projects until the state Capital Program Review Board approves our program - which can only happen when the City agrees to pay its fair share.

“I am tired of writing letters to City officials that result only in vague calls for more conversations. The sooner we can end these games and get to work on rebuilding our transit network, the better we can serve the 8.5 million customers who rely on the MTA every day.

Governor Cuomo controls the MTA, and some critics suspect Prendergast's attack is just another attempt on the governor's part to bare his teeth. It's true that the MTA's been struggling to fund its Capital Program, urging both City Hall and Albany to contribute a substantial amount of cash to keep things running smoothly. But the Mayor's office says that though Cuomo has pledged $8.3 billion to the fund, he still hasn't made it clear where that money will come from, and it should stand on the state to shoulder the burden.

"It’s irresponsible to play politics with people’s lives,” de Blasio spokeswoman Amy Spitalnick said in a statement. “The city stands ready and willing to have a comprehensive conversation on the future of this vital state authority, and we look forward to understanding where the promised state funding will come from.”

The good news is, the MTA was able to repair the track yesterday, and the G is now running as smoothly as it ever does.