ARTICLE 3 (AP) MONROE, La. (AP) -- Authorities started removing a dozen U.S. Army surface-to-air missiles early today from a truck that swerved across an interstate highway and crashed. Bomb experts from Barksdale Air Force Base, about 100 miles to the west, began taking the Hawk missiles off the flatbed and checking them for damage. "They off-loaded them into the middle of the interstate, where they will open up the crates and check the explosives," said Police Chief Joe Stewart. "Then they'll load them onto another flatbed." About 1,000 people were evacuated the area after the Thursday afternoon accident. "They'll be gone until the situation is under control. We're looking at a minimum of three hours," Stewart said. "If everything continues to go smoothly we can start opening things up around 6 a.m. (CST)." The truck also spilled some diesel fuel, which fire units washed down and covered with dirt and sand to prevent fire that could ignite the missiles, Stewart said. He said the only other thing that could set off the missiles would be compression. He said the shipment, with a driver and a backup driver, originated in Concord, Calif. It was en route to the Red River Army Depot in Texarkana, Texas, following stops in Illinois and Alabama. Stewart said the truck was owned by a private company contracted by the Army. Both of the truck's occupants were hospitalized in stable condition, but a supervisor at St. Francis Medical Center would not release their names. The accident, which occurred at 4:11 p.m., forced the closure of Interstate 20 for about three miles. "It was westbound on I-20, just entering the city limits," Stewart said. "For some reason we do not know at this time, the 18-wheeler crossed the median, crossed the eastbound lanes, jumped a 30-foot concrete canal, went through a chain link fence and came to rest under the carport of a house." "It is a classified shipment. It is not classified due to the explosives, but probably because of the technology," Stewart said. Stewart said he was not warned that the shipment would be moving through his city. "This military ordnance is shipped by interstate highway on a regular basis," Stewart said. "But on New Year's Eve, this came as a helluva surprise."