Spain train crash: What happened in the 17 minutes before the collision?

Following Wednesday's deadly train crash south of the Spanish capital Madrid, which killed at least 74 people and injured more than 100 others, investigators have uncovered new details about what happened. According to the latest findings, a few minutes prior to the incident, an IT failure disrupted communications and caused the LZB safety system to fail. The collision, which happened just before 9 a.m., on the Madrid-Seville high-speed line took place near the town of Urda in the central Spanish province of Toledo. The AV train run by Renfe ran into the back of an a train that was stationary on the same track. The LZB safety system transmits information between railway infrastructure and trains to monitor traffic and maintain safe distances. But alternative procedures are in place to manage train movements, according to a reconstruction published by the Ministry of Transport and communications a controller authorized the AV driver to resume his journey under normal running conditions even though the main signaling system had failed the government has initially suggested possible human error at a dispatcher's control center but responsibility has not yet been determined now investigators will need to establish whether operating protocols were correctly followed and why the AV was given an authorization to resume its journey.