A catastrophic fire at a Texas dairy farm has resulted in what may be the most significant single-incident livestock death toll in history. Southfork Dairy Farm in the state’s southeast suffered an explosion that took 18,000 head of dairy cattle, about 90% of the operation’s herd.

The farm’s 60 employees are all accounted for, although one employee was found trapped in the burning building and was life-flighted to a hospital, where she remains in stable condition. Investigators are trying to discern the cause of the explosion. Speculation points toward a piece of machinery possibly igniting methane gas.

Read more on the devastating fire here.