MIAMI--Eastern Airlines warned its pilots they risked their future by honoring picket lines in the two-day-old machinists strike, which has cut flights drastically, stranded weary passengers at airports and threatened to expand into a nationwide transportation snarl.

Eastern pilots, who virtually shut down the money-losing carrier by honoring picket lines of the striking machinists union, are risking not only their careers but "the very existence" of the airline, said Robin Matell, a spokesperson for Eastern.

"By continuing to stay out, the pilots are committing economic suicide," he said at a news briefing.

Eastern was hit with a strike at 12:01 a.m. Saturday by the Machinists union. About 8,500 mechanics, baggage handlers and ground crews walked out over Eastern's demand for contract concessions, escalating a 17-month union-management battle at the nation's seventh-largest airline.

Eastern ordinarily schedules 1,000 flights with 100,000 passengers daily. On Saturday just 85 flights took off; expectations yesterday were for 125 flights, Matell said. Nineteen had gone by 2 p.m., the pilots said.

The strike threatened to spill over into a union sympathy action against as many as 12 commuter railroads around the country, which could create rush-hour havoc Monday morning, especially in the New York metropolitan area. Strikers planned picketing at commuter railroads and received assurances no rail workers would cross their lines.

But U.S. District Judge Robert Patterson on Sunday signed a temporary order blocking sympathy strikes by workers at three railroads in the metropolitan New York area, said a spokesman for the Metropolitan Transportation Authority. The order was not made public immediately.

Ed Yule, general chairman of the United Transportation Union which represents conductors and trainmen on the Long Island Rail Road and Metro-North Commuter Rail Road, said his workers intend to obey the law. But he said he has asked the railroads to have any pickets removed.

If his members try to cross picket lines, Yule said, "they could get their heads bashed in, they could get their cars turned over, they could get their families threatened."

And U.S. Transportation Secretary Samuel Skinner, interviewed on NBC's "Meet the Press," said that if the situation warrants, the Bush administration will propose legislation eliminating provisions in the Railway Labor Act that allow secondary picketing.

In New Orleans, Thomas Hoggatt, president of machinists Local 1905, said it is too soon to tell how many other labor groups there will honor the strike.

"But we feel there is no tomorrow for the labor movement if they break us now," Hoggatt said. "There won't be a labor movement in the whole free world if we don't get someone's attention, if we don't get someone to listen."

"We feel very bad and certainly apologize for inconvenience to the traveling public, but the president obviously is ignoring his responsibility," Charles Bryan, negotiator for the machinists union, said yesterday on ABC's "This Week With David Brinkley."

In Atlanta, the Rev. Jesse Jackson urged President Bush to intervene and vowed to join machinists on the picket line this morning.

Yesterday, the busiest travel day of the week, scenes of anger and confusion were played out at Miami International Airport and at airports from San Juan, Puerto Rico, to Los Angeles and from Miami to New York. Some Eastern planes were stranded on Caribbean islands without crews, the company added.

Twelve commuter railroads nationwide and Amtrak were potential targets of sympathy actions.

In Boston, officials readied 150 public and private buses in anticipation of a sympathy strike that would affect service to 35,000 suburban commuters.

The Massachusetts Bay Transit Authority asked commuters to carpool, stagger work hours and rely on the buses only as a last resort because they could not accommodate the full load.

Pickets by machinists against Amtrak were expected in cities from Boston to New Orleans.