The Board of Audit and Inspection(BAI) has found that a considerable number of expressway overpasses are vulnerable to earthquakes. 

The BAI says the Korea Expressway Corporation neither conducted quake resistance tests nor installed anti-seismic reinforcement on more than two-thousand-100 expressway overpasses built before the government strengthened earthquake-resistant construction rules in 2000. 

The state auditor warned that when it conducted a quake resistance test of 22 of the overpasses, 15 failed under the stronger rules and could collapse if a quake struck.

An assessment of 24 express overpasses already retrofitted against earthquakes found nine of them were still vulnerable to seismic shocks.

The BAI says the Korea Expressway Corporation must take steps to ensure the safety of those overpasses immediately.