INS ARIHANT 2017

In 2017, India’s nuclear-powered ballistic missile submarine INS Arihant suffered a major accident when a hatch was left open while docked, allowing seawater to flood its propulsion compartment.
The result: critical damage to systems connected to its nuclear reactor, nearly $385 million in repairs, and the vessel out of commission for 10 months.
The culprit? A crew member who failed to follow standard protocols. The Indian Navy reportedly dismissed the employee quietly and without public proceedings.
Source: History Photographed