One employee witnessed a concrete slab above tank E610 crack as the emergency relief valve burst open, and pressure in the tank continued to increase to 55 psi (379.2 kPa) even after atmospheric venting of toxic MIC gas had begun.
Seorang karyawan menyaksikan lempengan beton di atas tangki E610 retak saat katup bantuan darurat terbuka, dan tekanan di dalam tangki terus meningkat hingga 55 psi (379.2 kPa) bahkan setelah ventilasi atmosferik dari gas MIC beracun telah dimulai.