Transcript for Aerialist Nik Wallenda details preparations for dangerous volcano tightrope walk
in the world. We saw it up close Monday and now NIK Wallenda is getting ready to walk over the 2,000-degree lake of lava, one of his most dangerous feats will reeve on the scene. Good morning, will. Reporter: Good morning, NIK Wallenda is nervous and it's understandable. If you'll take a look, this walk of the Masaya volcano over these whipping winds through the toxic gases above that boiling lava, it's all uncharted territory. I spent the day with NIK Wallenda learning about his process and preparation. The stakes are high. Almost 1,000 feet high. The reality is I'm risking my life. Reporter: Tomorrow night aerialist NIK Wallenda will attempt his most daring feat yet walking over one of the most volatile and dangerous volcanoes in the world, the Masaya. When you're at the middle and you look down -- will you look down? I absolutely will look down. It's more about this beautiful environment and this beautiful piece of nature. Reporter: Located in the heart of Nicaragua, the Masaya is one of the world's most active volcanoes. And this 1800-foot-long wire just over one inch thick will be the only thing between him and the lava lake below boiling at over 2,000 degrees fahrenheit. The last week in the middle of the night I'll wake up in cold sweats because of this walk. Every step is dangerous. Reporter: The plume of toxic gas is unpredictable and will walk street through it. I'll be wear goggles. What if they fog up. What if they're not affixed right and my eyes start burning. Reporter: Feats like this are a family generation. The 41-year-old has walked over the grand canyon and niagara falls and just eight months ago in times square. But the walk across the Masaya will be the highest and longest walk Wallenda has ever on a cable he hadn't seen before. I've never until this morning walked on a cable this diameter. Our cameras were there. Reporter: He took his first practice steps on that rusted wire. Wednesday night right about here. This is where it will all begin. What will go through your mind as you take these steps up? There will be everything from nerves to excitement, a little bit of fear. A lot of respect. It's a dream. Reporter: Wallenda told me the element that most concerns him is the wind because as he says it doesn't tell you how fast it's going, it's so unpredictable. The mouth of hell, those winds can come out of nowhere. We can't even watch that gulf right there. But what surprised you most about his state of mind as he's heading into this? Reporter: Well, I stood with him, George, at this wooden pyramid he's going to be climbing up as he begins his 1800-foot walk across the crater and his honesty about the fear that he will be feeling in that moment and that he's been feeling leading up to this waking up in those cold sweats, he told me he's going to be very scared but all he can do is literally put one foot in front of the other. He says he has to do this, It's almost reassuring to know he's going to be scareds. I mean he should be but it's an amazing, amazing feat, will. Thanks very much. You can see NIK walk over the volcano tomorrow live at 8:00 on ABC. We'll be right back.
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