The Queronque rail accident was a head-on train collision that happened on February 17, 1986, on the line between Santiago and Valparaíso in Chile. It is the worst in Chilean history, killing at least 58 people.^[1]

The accident happened in the Marga Marga Province of Valparaíso Region, between Peñablanca and Limache stations on a sharp curve. Both of the trains involved were three-carriage electric AES units and were carrying around a thousand people in total. The accident happened at 19:45 when the 17:30 from Los Andes to Valparaiso collided head on with a train travelling from Valparaiso to Mapocho Station in Santiago.^[2] The front carriages embedded themselves in each other for a distance of five metres, killing those at the front of both trains.^[3]

Repair work to a bridge damaged in an explosive attack by the FPMR^[4] six months previously meant that a single line was used for trains travelling in both directions.^[5] In addition, the signalling on the line dated from 1928 and had developed a fault a few days before the accident.^[3] But the accident was primarily blamed on the stationmaster at Limache, who should have held the train from Los Andes until the train from Valparaiso had passed.^[6] Theft of telephone cabling meant that the phone link between stations was not working,^[7] and it was over an hour before rescue teams arrived at the scene of the accident.^[4] The rescue efforts continued until 11:30 the following morning; an emergency hospital room was set up on the platform at Limache station; its speakers were used to ask for blood donors to come forward.^[3]

The official figures state that 58 people were killed and 510 injured, 111 of them seriously.^[6] However, some sources state the fatality figure to be much higher, 110^[5] and a recent video documentary puts it at 200.^[8]

Dictator Augusto Pinochet visited the injured in hospital shortly after the incident and pledged compensation to those affected similar to that in place for road accident victims.^[3]

As a result of the tragedy, the train service between Santiago and Valparaiso was suspended, only resuming in 1992 with the installation of radio communications in the trains.^[3] The line is now operated by MERVAL, the Valparaiso region metro system.