Ward was writing his journal when he noticed from information on a screen across from him that the train was going "very, very fast."
"We went round a sharp turn and all of a sudden you could tell one set of wheels left the rails," he said. "We were just riding on one set of wheels for two or three seconds."
Luggage started falling from the overhead racks "and then after one or two seconds, you could feel us leave the other set of the tracks and the train rotated about 90 degrees."
Ward blacked out before the train hit the ground, regaining consciousness only as he was being helped out of the train.
He registered nothing of the chaos inside and it took him a couple of minutes to grasp that what he was seeing outside was not a dream -- and that people were dead.
"They were helping out other people -- there were bodies, there was screaming, there was smoke."
The survivors looked like the walking dead, he said. "I've got staples all over my scalp, I was covered in blood. They've scrubbed most of it off me now but everyone was just covered in their own blood and occasionally the blood of others. It was gruesome to say the least."
Ward, who has already fought off a rare intestinal cancer, said he was very thankful to have survived this latest brush with death and he wants to continue his two-year mission in Spain.
Another victim, speaking from a hospital bed with his arm in a sling, told CNN affiliate Atlas that it seemed like the train was going fast.
"But we didn't know what was the maximum speed, so I thought it was normal," he said, "And suddenly there was a curve, the suitcases fell, and everything went dark. And I hit my head a ton of times, and 10 seconds later I was wedged between seats, and I had people's legs on top of me."
As he waited for rescuers to pull him from the wreckage, he heard other passengers yelling.
"I heard little children screaming. ... I also heard two girls that yelled out, one supporting the other," he said.
U.S. citizen killed on way to see her son
When the train crashed, Ana-Maria Cordoba was on the way with her husband and their daughter to visit her son, who had been on a pilgrimage in Spain, the Catholic Diocese of Arlington told CNN.
Cordoba, who worked for the diocese, was killed, spokesman Michael Donahue said.
Her husband and daughter are hospitalized in stable condition, the diocese said.
CNN's Houston affiliate KHOU named a couple from the Texas city, Robert and Myrta Fariza, as also being among the injured Americans.
According to an image it published of a note apparently posted on the door of their home, Myrta Fariza is in critical condition. Her husband was also injured but is "recovering well," it said.
Interim charge d'affaires Luis G. Moreno at the U.S. Embassy in Madrid said it was in touch "with families of some injured American citizens."
A British citizen was also among the injured, UK Foreign Secretary William Hague said.
The state rail company, Renfe, stated that 218 passengers were on the manifest. It's not clear how many crew and staff were aboard the train.
'We cry for the victims'
Spain's King Juan Carlos and his wife, Queen Sofia, visited a hospital in Santiago de Compostela on Thursday evening to meet some of those who were injured.
"All Spaniards, we are united at this time. ... Really all Spaniards join in the pain of the families of the dead," he said. "We hope that the wounded will recover, little by little."
The royal family canceled all events scheduled for the day out of respect for the day of mourning, the royal household told CNN.