Unless one of the leaks caused all the others, it seems like a hell of a coincidence for them to all happen on the same day by chance after sitting there for years.
The weight ist 13 tonnes steel + 13 tonnes concrete per segment, IIRC, diameter is 1.1m and segment length is 13m. Steel is ~7kg/dm³ => You can now calculate the wall thickness.
OK, OK, let's not talk: 130 dm * ((11/2dm + X)² - (11/2 dm)²) * \pi * 7kg/dm³ = 13000kg => X = 0.39dm
EDIT: Corrected the sign...