SAN DIEGO - Nobel Prize-winning scientist Francis Crick, who with James Watson discovered the spiral, "double-helix" structure of DNA, paving the way for everything from DNA blood tests to genetically engineered tomatoes, has died. He was 88.

Crick died Wednesday at University of California, San Diego, Thornton Hospital, according to Brendolyn Williams, a spokeswoman for the Salk Institute, the research body where Crick worked. Crick had been battling colon cancer.

It was 1953, while working in Cavendish Laboratory in Cambridge, England, that the British-born Crick, 36 at the time, and the American-born Watson, just 24, struck upon the famous double-helix structure - like a twisted ladder - of deoxyribonucleic acid, or DNA.

Not until years after the discovery were Crick and Watson's conclusions about the molecular structure of DNA firmly established. At the time, Crick later said, only a small number of people "even thought it was interesting."

A half-century later, the biotechnology industry is based largely upon Crick's and Watson's discovery. So, too, are genetically engineered foods like bigger tomatoes and innovative medical technologies like gene therapy.

Law enforcement agencies now routinely collect and test DNA from crime scenes, either to convict the guilty or set the innocent free. Social issues such as whether to have children are now often affected by expanded knowledge of DNA and its role in heredity.

The two were awarded the Nobel Prize in physiology or medicine in 1962.

In a statement Thursday, Watson hailed Crick "for his extraordinarily focused intelligence and for the many ways he showed me kindness and developed my self-confidence."

In person Crick was provocative, quick-witted and charming, although he rarely consented to interviews. He was averse to attention of any sort, he said, not because he was anti-social but because it cut into his thinking time.

Unlike many scientists, Crick did not spend his days toiling away in a lab or instructing students. Instead, he read and mused in his Salk Institute office overlooking the Pacific Ocean, putting in full days well beyond retirement age.