▁Ass am ▁to ▁P un j ab . ▁ ▁The ▁earth qu ake ▁was ▁so ▁severe ▁that ▁in ▁Kol k ata , ▁around ▁ 6 5 0   km ▁( 4 0 4   mi ) ▁from ▁ep ic enter , ▁many ▁buildings ▁were ▁dam aged ▁and ▁the ▁tower ▁of ▁St . ▁Paul ' s ▁C athedral ▁col lapsed . ▁ ▁Gr ound ▁effects ▁ ▁One ▁not ew orth y ▁phenomen on ▁of ▁this ▁earth qu ake ▁was ▁that ▁sand ▁and ▁water ▁v ents ▁appeared ▁throughout ▁the ▁central ▁v ents ▁of ▁the ▁earth qu ake ▁area . ▁The ▁ground ▁around ▁these ▁sand ▁f iss ures ▁subs ided , ▁causing ▁more ▁damage . ▁Ext ensive ▁li que f action ▁of ▁the ▁ground ▁took ▁place ▁over ▁a ▁length ▁of ▁ 3 0 0   km ▁( called ▁the ▁sl ump ▁bel t ) ▁during ▁the ▁earth qu ake , ▁in ▁which ▁many ▁structures ▁went ▁af loat . ▁ ▁In ▁Mu za ff arp ur , ▁sand ▁f iss ures ▁er upt ed ▁at ▁several ▁places ▁in ▁town . ▁The ▁well s ▁were ▁ch oked ▁with ▁sand , ▁while ▁water ▁levels ▁in ▁t anks ▁became ▁shall ower ▁due ▁to ▁sand ▁depos ited ▁in ▁the ▁tank ▁b eds . ▁Most ▁of ▁the ▁buildings ▁in ▁M uz za f arp ur ▁were ▁dam aged . ▁All ▁the ▁k ut cha ▁( ram sh ack le ) ▁buildings ▁col lapsed , ▁while ▁other ▁pu k ka ▁( sol id ly ▁built ) ▁buildings ▁suffered ▁damage ▁due ▁to ▁s inking