"Tonight Show" host Jay Leno will keep cracking jokes about train derailments until people "bombard him" with messages of disapproval, an Amtrak official recently advised railroad supporters.

The jokes also may end "when the audience stops laughing at them, and frankly, I think these jokes generally bomb, anyway," Clifford Black, Amtrak's director of special projects, wrote last month in an e-mail to rail buffs.

The discussion recalls a high-profile dispute in 1994, when Amtrak pulled $2 million worth of advertising from NBC in protest of jokes by Leno.

But don't expect a similar move this time: In his e-mail, Black wrote that Amtrak's 1994 strategy "backfired, big-time."

It's no joke that Amtrak is scrambling to overhaul its public image. After losing money throughout its 28-year history, the national railway must break even by 2003 to avoid a possible liquidation and a restructuring of intercity rail service.

Amtrak's uncertain future is a subject of concern on an Internet discussion group devoted to rail passenger travel. So is Leno.

In his memo to the list last month, Black wrote that he had received "several outraged e-mails" about jokes by Leno and CBS late-night host David Letterman.

Leno's jokes might stop, he wrote, "when members of the public (not Amtrak) bombard him with letters, e-mails, calls about how tasteless these jokes are."

He said grade-crossing accidents--collisions between trains and cars at intersections--spur the jokes, and "the only hope we have is to get sympathies turned around toward Amtrak and away from highway users, who cause most of the accidents."

Amtrak spokesman John Wolf said Black's e-mail was simply a reply to inquiries from rail fans.

"We're the public affairs department. We respond to what people say to us," Wolf said.

An aide to Leno said the comedian was not available for comment.

Black's e-mail was intended for limited distribution and is a far cry from Amtrak's very public response to Leno in 1994.

The day after Amtrak pulled its advertising, "Leno's entire monologue was about Amtrak accidents, replete with movies of staged head-on steam locomotive crashes from the 1920s," Black wrote.

There was also "a visit from the studio audience by a bandaged actor on crutches with fake blood all over him who was introduced as Amtrak president Tom Downs."

When Leno later brought his show to New York for two weeks of filming, he invited Black and another Amtrak executive backstage. Leno shook their hands and said he intended no harm.

Leno did not go cold turkey, but Amtrak jokes declined for about three years after that, according to Black.

Recently, though, rail supporters have posted messages on the Internet urging some form of protest against Leno for a rash of jokes.

The discussion was spurred by one writer's description of a "Tonight Show" skit portraying a toy Amtrak train derailing and killing people.

In one monologue in October, Leno quipped: "Did you hear that Amtrak is on the Internet now? Boy, if you thought your computer crashed before. . . ."

Earlier this year, commenting on Amtrak's plans for high-speed service between Boston and Washington, Leno said: "It'll go 150 miles per hour. That means you'll slide into the ditch 20 minutes ahead of schedule."

"It's almost like this guy has something personal against Amtrak--like Amtrak has done him some kind of wrong," wrote one ticked-off rail supporter from New Orleans.