The major metro disruption that shut down Amsterdam’s metro network for hours in early October was caused by the security system registering a train that was not expected and not actually there, NH reports. Safety protocols then required the entire system to be shut down.Metro lines 50, 51, 53, and 54 suddenly failed on the morning of Friday, October 2. The Noord/Zuidlijn was also temporarily halted. It took hours before the services resumed.