Colorado swimmer Sarah Thomas crosses North Channel twice, achieves world record

World-record swimmer Sarah Thomas did it again, as the Colorado ultra marathon swimmer and cancer survivor set another world record.

Thomas completed two crossings of the North Channel in Europe Sunday to become the first person in history recorded to do so. 

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After completing several open water swims around the globe, Thomas had her sights set on swimming the 21-mile strait between Northern Ireland and Scotland.

Thomas sent CBS4 a message shortly after her big accomplishment and said it was the hardest things she'd ever done — noting the jellyfish stings she had covering her body.

She was feeling good otherwise and was expected back in Colorado Monday.