morning. Courtroom, chris. It's difficult to imagine what lies beneath in stations all over like this one in manhattan. What you're about to see is a collection of everything that sandy brought to... See More
morning. Courtroom, chris. It's difficult to imagine what lies beneath in stations all over like this one in manhattan. What you're about to see is a collection of everything that sandy brought to bare. And water is the least of it. Deep underground, the beating heart of manhattan's transit system, now, an eerie labyrinth. All of this came with the water down the stairs? Absolutely. This wall here is from down here. Reporter: Man. It's got to weigh 200 pounds. Sandy's 14-foot surf washed into the south ferry station like a tidal wave, carrying thousands of pounds of debris. Are we talking about 50, 60 feet? Yeah. Talking about 2,000, 3,000 feet of track that's completely submerged. Reporter: This is just 1 stop, along 660 miles of subway track that carries more than 5.3 million commuters every day. At least three other stations have water up to their platforms. Many others have several feet of flooding. We have 46 miles of track currently underwater right now. Reporter: Underwater? Unusable? Yeah. Reporter: Remember, draining contaminated water, just the first step. Weeks it will take to pump this out? Yes. Reporter: And only then will you figure out the problems? Correct. Reporter: And above ground, cleanup is just as forbidible. You see that water? That's oil, and gas and transmission fluid. This morning, 250,000 people are still without power. Public schools remain closed. Nearly 4,000 utility workers from all over the country are rushing to new york today to help turn the power back on. You should not expect those people who do not have service today, to get service much before the weekend. Reporter: A weekend that should be one of new york's busiest, as thousands of people begin traveling across the world for the annual new york city marathon. A race, where just starting, matters much more than just finishing. We mentioned the marathon. It seems like a small thing. But in many ways, normalcy is measured by the little things. With the transportation system the way it is, it will be a race for the runners to get here. But the real marathon, josh, is the one that all of these thousands of workers are waging to get this city back on track, as they say. And that marathon is a long way from over, josh. Small steps, indeed. We cannot thank the first responders and all those helping enough.
This transcript has been automatically generated and may not be 100% accurate.