What happened

A buildup of 'popcorn polymer' ruptured a line at ExxonMobil's Baytown Olefins Plant around 11:07am, igniting a fire in an area handling polypropylene material. A precautionary shelter-in-place was issued for communities west of the plant and lifted a couple of hours later; 66 people were treated for non-life-threatening injuries with none requiring hospitalisation. This was an accidental industrial incident at a refinery-adjacent petrochemical complex, not an attack.

When cited sources give different casualty, damage or spill figures for this event, they’re reported side by side above rather than merged into one number. See how confidence levels work.