Nobel Prize-winning scientist Francis Crick (search), who with James Watson (search) 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 (search).

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 (search) 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."

"He treated me as though I were a member of his family," Watson said. "Being with him for two years in a small room in Cambridge was truly a privilege. I always looked forward to being with him and speaking to him, up until the moment of his death."

The discovery was retold in Watson's 1968 best-seller "The Double Helix."

Building on the work of Crick and Watson and others over the decades, scientists are now able to alter genes to breed out disease and breed in "desired" traits.

That newfound power has created ethical debates, but Crick said there was no way in the 1950s that he could have foretold modern DNA developments.

"Think of the effect television has had worldwide on politics," he said. "You can't possibly expect the man who invented the transistor to have seen that.

"You can just reckon that any powerful technique you invent, even if it is beneficial, is going to have effects much wider than you think, and it's going to have some disadvantages."

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. He had come to Salk after resigning from the Cambridge faculty in 1977.

Crick was born in Britain in 1916 to a shoe factory owner and his wife. He studied physics at University College and then built underwater mines for the British government during World War II.

After the war, Crick became interested in "the division between the living and the non-living" and decided to teach himself biology and chemistry.

In later years, Crick wrote "The Astonishing Hypothesis: The Scientific Search for the Soul," which had as its central tenet that everything we see, feel, think and experience is controlled by brain chemistry, not some inner spirit or will.

"Can you explain why blue looks blue?" Crick asked in the 1994 interview. "It's no use saying the sky looks blue. That doesn't say why it looks blue. Why doesn't it look red? ... That's a very difficult question.

"We are trying to go around that and find out what happens in your head when you see blue. Maybe that will give us a clue to answer these difficult questions."