Basically it was an unmodeled failure mode whereby the implosion of one sensor tube created a shock wave in the in-rushing water that radiated outwards, imploding all adjacent tubes in ever enlarging numbers until all the submerged sensors were broken. They'd considered hydrostatic pressure and modest over pressures in their design, but the shockwave pressures resulting from implosion were like 3 or 4x what they'd planned on.
Basically it was an unmodeled failure mode whereby the implosion of one sensor tube created a shock wave in the in-rushing water that radiated outwards, imploding all adjacent tubes in ever enlarging numbers until all the submerged sensors were broken. They'd considered hydrostatic pressure and modest over pressures in their design, but the shockwave pressures resulting from implosion were like 3 or 4x what they'd planned on.