Oven?
Italian Explosives Expert: The Beirut Blast’s Massive Red Cloud is Indicative of Lithium Metal Which is a Propellant in Military Missiles — IT WAS AN EXPLOSIVES STORAGE FACILITY
https://www.thegatewaypundit.com/2020/08/italian-explosives-expert-beirut-blasts-massive-red-cloud-indicative-lithium-metal-propellant-military-missiles-explosives-storage-facility/
(I have link to one surviving video with a working URL and it shows double blasts, first with boom, 2nd with whirling effect followed by huge BANG. What deflected the blast? The silo partial, the whirling pre 2nd Blast deflected the blast upward.)
Lithium is vey reactive. It will explode or catch fire on contact with water.