Travelers around the country were temporarily stranded Wednesday when Greyhound halted service after a bus crashed in Tennessee, killing at least six of the 40 people aboard.

The bus, en route to Florida, crashed 50 miles southeast of Nashville after a passenger aboard slit the driver's throat. The driver was treated for a cut to his neck and was stable after surgery, a hospital official said.

Greyhound issued a statement saying service would resume at midday -- but not before frightening and inconveniencing thousands of passengers around the country.

John Townsend, a businessman on his way to Seattle, said he was at the Fargo, N.D., terminal when the driver told passengers the bus would be delayed because of the crash.

"We thought he was joking," Townsend said. "Usually, I fly. But with what's been going on around the country, I thought it was probably safer to take a bus."

Justice Department officials said they did not believe the attack was terrorist-related, but the investigation was continuing.

Tim Barham, district manager of driver operations in Washington, D.C., said Greyhound already had begun boosting security in many terminals around the nation, testing out magnetic searches of passengers in Sacramento and Dallas, for example. He said cameras had been installed in Washington as well.

"Ever since the September 11 events we've had several discussions and started to implement extra security," he said.

In Denver, Colo., 100 to 150 passengers crowded the Greyhound station, some sitting on luggage, while others smoked, played video games or grabbed something to eat. Pay phones were in high demand.

Russell Lewis of Aurora, Colo., was going to Longview, Texas. He said he usually takes the bus because he doesn't like flying.

"And since all that junk went on, that pretty much sealed it," he said, referring to the Sept. 11 attacks on the World Trade Center and the Pentagon.

Passengers aboard a Toronto-to-New York City bus said they were pulling into the Binghamton, N.Y., station when their driver told them about the deaths.

"All of us were petrified," said Maria Antonio of Toronto. "You never know what's going to happen."

Even before service was shut down, some customers were refusing to get on their buses in Portsmouth, N.H., after they heard about the crash.

"People are a little panicky about it," Joi Smith, a Greyhound agent, said. "They are freaked out, which is understandable."

Arron Cross, waiting at the Nashville Greyhound station for a car ride home to Memphis, said he was surprised when he got on the bus in New York City and no one searched his bag.

"I don't know what's safe now. I'm going to start taking a car," he said.

AP-WS-10-03-01 1233EDT