Audio recordings reveal decisions made moments before deadly train crash in Spain

New audio obtained by Spanish media reveals that the operator of a stopped train called a control center to say she could not restart the train as another behind it sped ahead in its direction. The resulting crash of the two high-speed trains Wednesday killed at least 69 people and injured dozens more.

Many questions remain about the failures that led to one of Spain’s worst transportation disasters in decades, and whether something could have been done to prevent the crash. Audio recordings of communications between the train operators and staff at a control center in Madrid shed light on the decisions made in the minutes before the trains collided.

Spain’s transportation minister, Óscar Puente, said Wednesday that a security system stopped working because of a computer malfunction, causing multiple trains on the line to stop at about 8:30 a.m. local time. With the computer system down, rail traffic was then handed over to the control center in Madrid.

At approximately 8:36 a.m., the control center authorized a state-owned Renfe high-speed train to resume its journey, without speed limitations, despite the fact that there was a stationary ‌train from private rail company Iryo on the tracks ahead, Puente said. An erroneous ​decision was ‌made ⁠to restart the ⁠Renfe train, breaking protocol, he said.

Audio obtained by Spanish media of the conversations between the operators of both trains and the control center sheds light on the series of decisions leading up to the collision at about 8:53 a.m., near the train station in Urda. NBC News has not been able to independently verify the authenticity of the audio.

After the computer system went down, the control center told the Renfe train operator to resume its journey “at normal speed,” according to an audio clip.

“At normal speed? OK,” the operator responded.

“OK, we’ll talk later,” the controller said before signing off.

Several minutes later, someone from the control center called the Iryo train to authorize it to also continue on its normal journey, according to an audio clip.

The operator of the Iryo train, which was ahead of the Renfe train, called back seven minutes later to say she had been unable to restart the train. “I’m still stopped at the entrance signal,” she said, according to the audio clip. The control center then told her to restart the train when she can and to call back if she has further problems, according to the audio. Several minutes later, the Renfe train collided with the back of the Iryo train.

The crash, the second deadly high-speed rail train collision this year in Spain, sent shock waves across the country. Until recently, the high-speed rail network was considered one of Spain’s crowning achievements. The crash came just weeks ahead of a major election in Spain and has led to criticism of the current government and protests.

In January, a separate disaster on the same rail line killed 46 people. Several days later, a commuter train near Barcelona derailed, killing the driver and injuring dozens.

Hundreds of emergency workers, firefighters, police and soldiers attended the scene of Wednesday’s crash to rescue survivors and recover bodies, before cranes were brought in to move parts of the damaged trains later in the day.

Spain has the largest high-speed rail network in Europe for trains moving at speeds of more than 155 mph, with more than 1,900 miles of track, according to the European Union.

The country is observing three days of mourning after the crash.