On Wednesday, Kolkata Metro achieved a historic feat by running a train through a tunnel under the Hooghly river for the first time in the country. The senior official in charge reported that the Metro train, which carried only officials and engineers, successfully traveled from Kolkata to Howrah on the opposite side of the river. Kolkata Metro's General Manager, P. Uday Kumar Reddy, hailed the event as a significant moment for the city, and he emphasized that this is only the beginning. Regular underwater trial runs on this route will soon follow. The route between Howrah and Esplanade covers a distance of approximately 4.8 kilometers, with 520 meters of that distance running through the tunnel beneath the Hooghly River. The tunnel's depth is 32 meters below the water's surface level. This achievement is a significant milestone for Kolkata and sets a precedent for similar infrastructure projects in the future.