The officials testified Wednesday in the trial of Tyrone Williams, who is accused of abandoning the truck in south Texas and causing 19 immigrants to die in May 2003.
''I'd never seen that many bodies before in one situation,'' said Rick Streeter, a firefighter and paramedic with the Cold Creek Volunteer Fire Department.
One of the survivors of the smuggling attempt testified Wednesday that he and the other immigrants wanted desperately to get out of the airless trailer but that Williams ignored their screaming and pounding on the vehicle's walls.
Craig Washington, Williams' lead attorney, has said his client couldn't understand their pleas because he doesn't speak Spanish, but when Williams found out what was happening, he tried to help by giving them water.
On a copy of a surveillance videotape that was played for jurors Wednesday, Williams and a female passenger could be seen buying 55 bottles of water at the truck stop where the trailer was abandoned.
Dr. Roberto Bayardo, the chief medical examiner for Travis County who performed autopsies on the victims' bodies, said the immigrants needed air - not water - to survive.
If the immigrants had been in a cooler environment, their chances of survival would have been greater, he said. Prosecutors have previously said the refrigeration unit on Williams' trailer was not turned on.
Williams, 34, a Jamaican citizen who lives in Schenectady, N.Y., is being tried on 58 counts of harboring and transporting illegal immigrants. He could get the death penalty because federal law allows capital punishment in fatal smuggling cases.
