An explosion tore through the sole bridge linking the Russian-occupied Crimean Peninsula to Russia, collapsing a part of the span into the sea and imperilling a primary supply route for Russian troops fighting in the south of Ukraine.

The 19-km-long Kerch Strait Bridge is a cherished political project of President Vladimir V. Putin and had become a potent symbol of theclaims that Putin makes to the peninsula, which his forces illegally seized from Ukraine in 2014.

Putin presided over the opening of the bridge in 2018, personally driving a truck across. The extent of the damage was difficult to immediately assess, though any impediment to traffic on the bridge could have a profound effect on Russia’s ability to wage war in southern Ukraine. Videos showed the railroad burning and two of four lanes of the roadway collapsed into theBlack Sea, where waves lapped the asphalt.

The Russian Railways company said all trains to and from Crimea have been temporarily cancelled, the state news agency Tass reported.

The bridge is the principal military supply route linking Russia with the Crimean Peninsula. Without it, the Russian military will be severely limited in its ability to bring fuel, equipment and ammunition to its units fighting an increasingly intense battle for the control of southern Ukraine.

Russia still controls roads on overland routes from Russia into southern Ukraine, but those are within the range of Ukrainian rocket artillery. Russia’s National Anti-Terrorism Committee said in a statement that a truck had exploded on the bridge, igniting seven fuel cisterns being pulled by a train on a parallel railroad crossing headed in the direction of Crimea and causing two car spans to partially collapse.

Preliminary information suggested that three people were killed, Russia’s investigative committee said in a statement. While there were no immediate claims of responsibility, Russian and Ukrainian officials indicated that the fire was no accident.

New York Times News Service