What happened

Entrapped gas exploded in the floating roof of a naphtha storage tank during post-maintenance work at TÜPRAŞ's Aliağa refinery. Four contractor employees were killed. TÜPRAŞ and Oil & Gas Journal reported one additional worker injured, while some early Turkish reporting counted two injuries; this record therefore states at least one. The tank had been emptied and out of service before maintenance. Local authorities described the explosion as an industrial accident caused by gas pressure and said no wider fire or leak affected refinery operations. TÜPRAŞ opened an investigation and said it would review its work processes and safety arrangements.

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.