A 20-inch main broke in a transit tunnel at Northern Boulevard and 40th Road, just after 11 p.m.
The result was no service from the Queensboro Plaza Station to the Astoria Ditmars Boulevard station for roughly four hours.
Riders say they didn't know why service was disrupted.
And some were forced to walk home.
"I waited for a train and it never came. I don't know why the train was stopped, they didn't tell me anything," said one rider.
"We had to walk two miles at home at midnight when I was expecting it would be a five-minute train ride," another rider said.
Regular service was restored early Sunday morning.
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