For the couple standing vigil beside a collapsed highway bridge, the waiting was harder than knowing if their loved one was among the seven people killed when the 55-year-old span gave way.

"They brought up a piece of car that was the same color as his," Paul Hurst said Monday as searchers continued looking for victims in the rain-swollen Hatchie River.Seven bodies have been pulled from the river since the bridge collapsed Saturday night. But authorities were continuing their search Tuesday, operating under the belief at least one more car is still submerged.

Hurst said his half-brother, Adrain Jones, 26, has not been seen since shortly before a 90-foot section of the U.S. 51 bridge fell, sending cars and a tractor trailer rig plunging 25 feet into the water.

"He left the hospital and I went to Memphis the same time," said Hurst, who with his wife, Brenda, has been waiting beside the river since they first heard of the bridge collapse a few hours after the accident.

Authorities said they, too, are working on the assumption that Jones' car is somewhere in the dark, swirling water.

Monday, a dog trained to sniff bodies appeared to find something. Authorities planned dragging operations this morning. Divers were forced to wait because of strong currents in the river, about 50 miles north of Memphis.

Also Monday, workers began cutting up the three 28-foot bridge spans. When the 100-ton concrete slabs are jackhammered into manageable pieces, a crane will be brought in to remove them, said Jim Thacker, regional manager of the Tennessee Emergency Management Agency.

The cause of the collapse was unknown, but state Transportation Commissioner Jimmy Evans said heavy spring floods following two years of drought may have undercut a bridge support. Two inspections during the last 18 months revealed no problems, he said.

The collapse apparently began when a support holding up one of the bridge sections gave way, said Jacky Carter, a state inspector.

As the cars and the 18-wheeler plunged off the bridge, the other two highway sections came crashing down on them, he said.