"Dozens of firefighters are working to put out a blaze that is burning at an oil depot in St. Petersburg, Russian authorities said.
Videos from the area posted on social media show a large plume of black smoke rising as explosions ring out.
The fire was first reported at 10:59 a.m. local time, Russia’s Ministry of Emergency Situations said. A hangar of 80 by 10 meters (262 by 33 feet) was reported up in flames the ministry said. [snip]
Russian infrastructure such as oil depots have previously been targets over its invasion of Ukraine." (our emphasis)
Obviously another careless smoker, or high temperatures.
(photo: Ruchi oil depot on fire. Ukraine News)