A group of Bay of Pigs combatants plans to file a lawsuit today against Fidel Castro and one of his top commanders.

BY EVAN S. BENN

It was 46 years ago, but the survivors remember all the gruesome details of their ride inside a sealed semi-trailer following the failed Bay of Pigs invasion.

Urine and excrement sloshed on the floor, and men and boys -- more than 100 men captured by Cuban militia -- took turns breathing fresh air out of a small hole someone punched in the truck's side.

When the truck stopped eight hours later in Havana, nine of the men inside were dead.

Today, Miami-based survivors of the invasion plan to file a lawsuit against Cuban military commander Osmany Cienfuegos, who they say gave the order to pack the men into the truck -- and Fidel Castro.

''We believe we have enough proof that the crime was committed by these two individuals,'' said Juan R. López de la Cruz, a retired U.S. Army colonel and Bay of Pigs veteran who lives in Miami.

López de la Cruz spoke to The Miami Herald on Sunday from Madrid, where the group is planning to file the lawsuit this morning.

The invasion veterans want their case heard in a Spanish court, which has asserted jurisdiction for human rights abuses in countries around the world. A similar court indicted former Chilean dictator Augusto Pinochet.

''We hope the Spanish courts will listen and will recognize that this is a very clear-cut case,'' López de la Cruz said. ``Hopefully, the men responsible will receive the justice we are asking for.''

The group wants the court to hold Castro and Cienfuegos responsible for the deaths of those nine prisoners of war.

Because he has ceded head-of-state powers to his brother Raúl, Castro may no longer be immune to charges from the lawsuit, the group said. Cienfuegos, who is in his 70s, is a member of Raúl Castro's inner circle.

People who witnessed the truck ride claim they heard a Cuban officer warn Cienfuegos that the truck was overloaded and had no air.

''Let them die. I don't care,'' they remember Cienfuegos saying as he ordered the officer to shut the doors.

The truck ride happened days after the April 1961 Bay of Pigs Invasion, the U.S. government's failed plan to overthrow Castro. López de la Cruz and others were captured near Girón Beach and were taken to Havana.

They were packed into a trailer normally used to transport tobacco leaves, outfitted so it sealed in moisture and kept out fresh air. Soon into the trip, condensation from the men's sweat accumulated on the truck's ceiling and dripped down on them.

When the truck unloaded the men in a Havana stadium, Castro was there, witnesses said, and he saw the men's condition. Most of them were sent to Cuban prisons but were released about 18 months later as part of a deal with the United States.

''I'm thrilled it has progressed to this point,'' said William Muir, 63, a Kendall resident who was with López de la Cruz in the semi-trailer in April 1961.