the coach just breaking apart is a serious issue... thank god it broke in yard , if it broke during run then train would have derailed but we wouldnt had never got the reason for derailment... because coach get totally broken after derailment ..
who knows , some derailment in past might have occurred just because of old/faulty coaches .. 25 years is too long , i think 20 years is the maximum life ... IR has scarcity of coache yet 100 new trains are announced every year ...