soldier's foot

Last few days, an accident happened on a military exercise. One of 25 tanks, the amphibious BTR 5O made in Russia sank in the Situbondo sea. There are several claims of why it happened. It's pure of accident. The others say it's all old military equipments the army use for a long period. Moreover, it's been modified with other components produced other not from original producer, Russia.
It's a faber-castell.