Cairo, April 13 : Egypt's Public Prosecution has revealed that human errors and gross negligence by railway staff led to the deadly collision of two trains last month in Sohag province, which claimed the lives of 20 people. On March 26, a Spanish train crashed into the back of a standing one, leaving 20 people dead and 199 others wounded, and resulting in losses which have been estimated at more than EGP 25 million. The prosecution on Monday revealed that the driver's assistant of the moving train and the person in the watchtower who was in charge of changing the train's course at the site of the accident have been under the influence of narcotic substances. A drug test showed the two persons had taken cannabis and tramadol. Meanwhile, the driver and assistant in the train that caused the crash were not inside the driving cabin at the moment of the accident, the investigation results revealed. It added that the chairman of the control department that is responsible for monitoring the movement of trains was not present in his place at the time of the crash either. The prosecution probe also said that the two trains' Automatic Train Control (ATC) systems were deactivated. However, the railway officials have confirmed that the ATC systems are not usually stopped in the area of the accident. /IANS