A piece of aluminum led to an explosion-like sound and triggered panic among passengers inside the Dum Dum-bound metro train at Mahatma Gandhi Road on Thursday, feel the railways engineers.
"Our engineers carried out a detailed inspection till the early hours of Friday and noticed there were no snags in the rake. They returned to the spot of the incident and found a piece of aluminum on the third rail," said Protyush Ghosh, Metro Railway spokesperson.
"Our investigation revealed that the piece of aluminum got sandwiched between the third rail and one of the compartments. When the train started, there was friction. This resulted into a mechanical fault in the electrical network," said a Metro rail engineer. The lights and fans inside the train also went out.