UPDATE: He made it! After nearly 23 minutes, Nik Wallenda is the first human to ever cross the Little Colorado River Gorge on a wire.

Daredevil Nik Wallenda has a wife, three children, and he's been training for one moment his entire life:

To tightrope walk across the Grand Canyon without any safety net or harness. Making it across means life, falling means death.

The National Park Service would never allow a stunt like this over the Grand Canyon — so Wallenda had to settle for the "little Grand Canyon" over the gorge of the Colorado River near Cameron, Arizona, on tribal lands of the Navajo Nation.

Wallenda's grandfather died before viewers' eyes on live television trying to do a similar, harness-free walk.

"Thank you Jesus," Wallenda kept repeating with each step. "You're my king, you're my protector, you're my shield, you're my strength, you're my lord." He battled high winds and balanced with a 45 pound bar on the 2-inch wire. He reached the half-way point on the wire at the 11:30 minute mark.

The quarter-mile walk at 1,500 feet in the air took more than 20 minutes — in winds ranging from a safe 18 mph to a more treacherous 30 mph. Wallenda knelt twice to wait out the stronger wind.

Here's his bio on Discovery's website:

Nik Wallenda is known as 'The King of the High Wire.' He is the seventh generation of the legendary Great Wallendas and began walking the wire at age 4. He and his family have performed some of the most famous stunts in the world, but no one else has ever dared to take on the Grand Canyon.

His incredible walk was aired on the Discovery Channel Sunday evening on a live feed.

This isn't the first feat on the tightrope for Wallenda. Last year, he successfully walked across Niagara Falls, according to NPR.

Here are some shots of him crossing the canyon.