We have no cause info.
By process of elimination, CTX believes this is the ship
referred to by Embiricos, page 23.
Embiricos refers to a partly loaded 90,000 tonner
which grounded in the mid 70's in the Suez Canal,
holing 1P and 2P, and losing 17,000 barrels.
After refloating and clearing the Canal,
the ship transferred some cargo to intact tank,
and proceeded to final port of discharge.
Embiricos can't recall which ship it was;
but this is the only casualty that comes anywhere
near this description, and it matches quite well.