"It was like a car hitting the house or an explosion. It shook that much," said John Ferolito, 60, of Carrolton, north of Dallas.

NASA declared an emergency after losing communication with Columbia as the ship soared across Texas at an altitude of about 200,000 feet while traveling at six times the speed of sound. All seven astronauts aboard the shuttle were killed.

"We went outside to see if it was landing. We saw a streak going across the sky," said Chris Linville, 21, who was in Addison, north of Dallas. "From the viewpoint we had, we did see some flames."

Doug Ruby and his father were driving along a Texas highway, headed off on a fishing trip, when they apparently caught sight of the shuttle.

"We saw it coming across the sky real bright and shiny and all in one piece. We thought it was the sun shining off an airplane," Ruby told The Associated Press. "Then it broke up in about six pieces, they were all balls of fire, before it went over the tree line,"

Gary Hunziker in Plano said he also saw the shuttle flying overhead.

"I could see two bright objects flying off each side of it," he said. "I just assumed they were chase jets."

"I was getting ready to go out, and I heard a big bang and the windows shook in the house," Ferolito told the AP. "I thought it was a sonic boom."

Sen. Kay Bailey Hutchison said she heard a loud boom Saturday morning while out walking in her Dallas neighborhood.

"I heard this boom, which I thought was the breaking of the sound barrier, which I've heard many times because we have F-16s here," she said. "I've heard screams and sonic booms before and that's what I thought it was and then I came home and turned on the television."

Elbie Bradley was fishing alone on the foggy Toledo Bend reservoir along the Louisiana-Texas state line when he heard something that "sounded like it was fluttering through the air."

The object made "a good splash" near his boat.

"I had no idea. I thought it was an airplane that hit the lake. Before the piece came down, it sounded like the start of a big motor without an exhaust on it," he said.

He picked up his anchor and went back to his dock. A neighbor heard the explosion and called 911. Shortly afterward, television reports came in that the shuttle had broken up, Bradley said.

Police in Arkansas and Louisiana both reported getting calls about the explosion. Louisiana State Police in Bossier City, 182 miles east of Dallas, got so many calls that one trooper had to be assigned just to answer the phone.

"One said he saw a plane breaking up over Shreveport. One said he saw a big ball of fire," state police Sgt. Steve Robinson said. Another caller said a blast "shook his house."