As Hurricane Sandy bore down on New Jersey, NJ Transit moved many of its trains to rail yards in Kearny and Hoboken — lowlands easily flooded by the hurricane’s surge. When the storm was over, $120 million worth of trains were damaged.

Ever since, NJ Transit insists it couldn’t foresee that kind of surge — despite forecasters’ warnings.

Now there’s evidence NJ Transit ignored its own emergency hurricane plan — which calls for moving trains to much higher ground to protect them from rising floodwaters.

Sen. Loretta Weinberg (D-Bergen) says legislative oversight hearings into the agency’s expensive mistake will take place by the end of September. She wants accountability for what proved to be a colossally bad call.

As Sandy approached, NJ Transit moved its trains to repair yards in the Meadowlands and Hoboken. Officials say neither location ever flooded before Sandy. Nonetheless, a third of its fleet — 70 locomotives and 273 cars — were damaged.

Last week, NJ Transit released its hurricane plan, written four months before Sandy. It calls for trains to be moved to higher ground, not to lowlands where they might be overwhelmed by surging waters.

Hurricane Sandy caught many of us off guard. Few were prepared for the size or duration of the superstorm and its surge, which wiped out homes up and down the Jersey Shore.

But NJ Transit had fair warning: Forecasts predicted the surge, and the agency’s own documents recommended a course of action far different from the one it ultimately took.

Gov. Chris Christie said this week that he hadn’t known about NJ Transit’s hurricane plan. The governor’s been applauded for his pre- and post-Sandy efforts, and no one expects he read each agency’s plans. But he should expect his lieutenants have such plans — and that they’re followed. And when they aren’t, Christie should want answers, too.

FOLLOW STAR-LEDGER OPINION: TWITTER | FACEBOOK