Spanish police have arrested the driver of the speeding train that crashed earlier this week, killing 78 people and injuring more than 140 in one of Europe's worst rail disasters. Police say they plan to question him for "recklessness."

Jaime Iglesias, the national police chief of the Galicia region, said Francisco Jose Garzon Amo, the 52-year-old driver, was being questioned Friday as a "suspect for a crime linked to the cause of the accident."

The police investigation comes amid Spanish and other media reports that the driver boasted on an old Facebook page about being able to get a train to reach high speeds.

His Facebook profile, which has since been removed, showed a March 8, 2012, picture with the needle of a speedometer pointing at 200 km/h. He responded to some comments on the page by saying, "It's the limit. I can't go any faster or I'll get a ticket."

The train in Tuesday's crash reportedly is able to reach speeds of up to 250 km/h. The speed limit on the curve where it derailed is 80 km/h.

Police have also taken possession of the train's black box that is expected to shed light on why it was apparently going faster than the speed limit on the curve where it derailed.

The box records a train's trip data, including speed and distances and braking and is similar to flight recorders used on commercial airplanes. Court spokeswoman Maria Pardo Rios said analysis will be performed on the device, but she declined comment on how long it will take.

Survivor describes 'gruesome' scene

U.S. Mormon missionary Stephen Ward was living a nightmare when he awoke from his blackout and saw dozens of fellow passengers crying, bloodied and in pain after a deadly train crash in Spain this week that has led police to detain the hospitalized driver as a suspect. 

Ward, an 18-year-old from Utah, was injured in the crash in Spain's Galicia region on the outskirts of the regional capital, Santiago de Compostela. However, he told CBC News in a phone interview Friday after his release from hospital that he's "on the mend" and grateful he's alive, since dozens died in the tragedy.

"My overwhelming emotion is gratitude that it wasn't worse for me," said Ward, who left hospital in a neck brace. "I was not the only one covered in blood. There were lots of people crying. Lots of people in a great deal of pain. It was pretty gruesome.

"I'm grateful that I came out so well. I'm sorry so many people passed away. I was the last person they pulled away in an ambulance."

Train's speed in question

Ward was quoted in an earlier report by another media organization as saying he saw on a TV monitor screen inside his car that the train was travelling 194 km/h seconds before the crash.

'I have some good bruises, some scrapes … a neck brace, but nothing that won't heal on its own.' —Train crash survivor Stephen Ward, 18, Utah missionary

However, he told CBC News that he's now not certain of the speed on the screen before the derailment.

For most of the ride, the speed was at about 100 km/h, he said. At one point, minutes before the crash, he looked over at the screen, which was on the other side of the car, and it appeared to show 194 km/h.

"The sun was kind of shining off it, and I don't have the best eyesight, so I thought, 'Oh, that can't be right. It must be 104.'

"It didn't feel that much faster, but it could have been, adds Ward.

I was writing in my journal at the time, so I wasn't paying that much attention to speed."

Civilians also helped crash victims

Ward said that before the crash, the train started leaning to one side for a couple of seconds.

"We had just gone around a couple of sharp curves, and so first it seemed like one more sharp curve and you could feel one set of wheels lift up off the tracks. There wasn't screaming or anything, but people were just kind of, like, 'Whoa, we're leaning pretty hard.' And then we flew off the rails.

spain-train-wreck-locator

The pilgrimage destination of Santiago de Compostela in northwestern Spain was the scene this week of the country's worst train crash in decades. (Google Map/CBC)

"It was all very sudden," he adds.

After the crash, he blacked out for a few minutes.

"The next thing I remember is them helping me out of the car," he said. "I was very lucky. My car ripped apart from one of the cars next to it, so they were able to help me out through a door rather than a window. And I was one of the first people they got out. I thought it was a dream ….

"They helped me out of the car and out onto a little bank of land nearby [the crash]

. And I was there for a couple of minutes before I began to suspect, 'I think this is real life. I think this train just crashed.'"

After coming out of his blackout and witnessing the mass carnage, Ward noticed the paramedics and some civilians who had also come by to help crash victims. 

"I have some good bruises, some scrapes … a neck brace, but nothing that won't heal on its own."

In the meantime, the driver is under guard by police, who say he cannot yet testify because of his medical condition.

He reportedly had a flawless record, helped rescue some of the injured, and told a radio station after Tuesday's crash that, "I hope there are no dead or it will weigh heavy on my conscience."
With files from Reuters and The Associated Press