Texas officials struggle with mounting number of debris sites.

Officials in eastern Texas are struggling to locate and secure the hundreds of pieces of shuttle debris that are being found.

Nacogdoches County Sheriff Thomas Kerss says the area "cannot muster enough manpower" to possibly guard each of one thousand sites reported so far.

Kerss says officials are working to identify any site that might offer important data, pose a health hazard or hold astronaut remains.

He says those sites will be guarded by volunteer firemen, law officials, National Guardsmen or other officials -- until federal authorities arrive to pick up the debris.

Debris from Columbia is spread over at least 500 square miles, and residents from suburban Dallas to the hilly pinewoods of Louisiana have reported finding bits and pieces of the shuttle.

One hospital worker says he's found what appear to be a charred torso, thighbone and skull on a rural road, and two young boys have reportedly found a charred human leg.

Investigators are telling residents to report any debris but not touch it for fear of contamination from toxic substances.

They say bits of the wreckage could be pivotal in determining what caused yesterday's disaster.