Columbia began to lose parts over California: radar images WASHINGTON (AFP) Feb 19, 2003 Radar images show the space shuttle Columbia began to lose parts over California some seven to eight minutes before it disintegrated on re-entry February 1, the independent commission investigating the disaster said Tuesday. "It does look like things were beginning to come from the shuttle as it approached right above California," James Hallock, a member of the Columbia Accident Investigation Board, told a NASA press conference in Houston, Texas. Engineers are still trying to "extrapolate" where pieces from the shuttle may have landed before the shuttle broke up on re-entering the earth's atmosphere, killing all seven astronauts on board, he said. The radar images coincide with video footage showing the partial disintegration of the ill-fated Columbia as it passed over California, Arizona and New Mexico, before bursting apart in flames above Texas, Hallock said. Volunteers and members of local law enforcement agencies have launched an extensive hunt for all debris from the shuttle. "It would be very important to understand what those pieces are, particularly the ones that started falling off at the beginning," he added. Investigators are examining a series of theories to explain why the disaster occurred. The most convincing so far is the so-called thermal breach theory, which suggests that the left wing of Columbia was probably pierced, allowing "super-heated" air into the shuttle's cabin just before it broke up. Air and gas reaching temperatures of around 2,000 degrees F (1,100 degrees surrounds the space shuttle as it re-enters the atmosphere, and experts now believe this "plasma" breached the shuttle's skin near its left wheel well on February 1.