Tightrope walker Nik Wallenda starts out on his wire walk from Marina City’s west tower to the top of the 671-foot-tall Leo Burnett building (50 storeys)on November 2, 2014 in Chicago, Illinois.

US daredevil Nik Wallenda broke two world records Sunday when he crossed the Chicago skyline on a tightrope suspended between three skyscrapers, without a safety harness.

Wallenda, already the first person to cross the Grand Canyon and Niagara Falls on a high wire, set records for the steepest tightrope incline and highest blindfolded walk as he stepped gingerly across the Windy City in mid-air.

In the first half of the stunt Wallenda, 35, walked more than two city blocks and crossed the Chicago River with a tightrope set at an incline of 19 degrees, between the Marina City west tower and the Leo Burnett Building.

Daredevil Nik Wallenda

Upon descending from the tightrope, Wallenda returned to Marina City west via the ground to complete his second and more dangerous feat: a tightrope walk to the east tower at more than 500 feet (152 meters), blindfolded.

He completed the first walk in just under seven minutes and the second in slightly more than a minute, despite gusts of wind.

“It’s all about pushing myself to become better at what I do and hoping to inspire others to become better at what they do,” Wallenda told the Discovery Channel, which broadcast the stunt in more than 220 countries.

The Chicago Tribune said police estimated some 50,000 people turned out to watch Wallenda, a seventh generation member of the Flying Wallendas circus family.