The mishandling of the biggest Arctic oil spill ever infuriated Russian President Vladimir Putin and could give a boost to the country’s environmental regulation. MMC Norilsk Nickel PJSC, Russia’s biggest miner, didn’t make a public statement until two days after the May 29 accident, which leaked over 20,000 tons (150,000 barrels) of diesel into a fragile Arctic river system. By then, images of the catastrophe had gone viral on social media and soon the governor of the region made a public report to a visibly irritated Putin. The president publicly scolded Vladimir Potanin, Nornickel’s biggest shareholder and the country’s richest man, for not upgrading the tank before it leaked.

relates to Putin’s Fury Over Diesel Spill May Force Green Reform in Russia

Images from the the Copernicus Sentinel-2 satellite show the extent of the Norilsk spill.

As the extent of the spill became clearer, investigators said Wednesday that they’d detained several employees of the unit responsible for the tank, a move Nornickel called excessive. The company has said melting permafrost and soil subsidence damaged the tank. If true, that means infrastructure across the country’s vast north may be at risk as the ground warms.

Nornickel has long been criticized for ignoring environmental issues. A small investment in the tank might have prevented the spill, which now threatens extinction for many fish, birds and mammals unique to Siberia’s Taimyr Peninsula, a senior official said. Putin was very angry over the spill, according to the person, who asked not to be identified in order to speak candidly.