sentences:  In November 2019 Norilsk Nickel announced plans to cut sulphur dioxide emissions in the region by 90% by 2025 from 2015 levels.On 29 May 2020, a fuel storage tank owned by Nornickel subsidiary Norilsk-Taimyr Energy (NTEK) collapsed, flooding the nearby Daldykan River with up to 21,000 cubic metres (17,500 tonnes) of diesel oil.Russian President Vladimir Putin declared a state of emergency.