Seoul would be heavily hit, but US counter-battery fire (including air strikes) would silence the NK artillery after a while.
It seems like a good investment in Seoul would have been underground bunkers.
Do you know if they ever got around to building these in Seoul? Seems like these could withstand temporary bombardment, until we could get the artillery shut down.
Russia has done this recently by building 400 sq miles of bunkers for it’s populace in case of nuclear war.
“Sweden is set to bring hundreds of Cold War-era nuclear bunkers out of mothballs as tensions with Russia in the Baltic are ratcheted up another notch. More than 60,000 nuclear bunkers were built after 1945 to protect Swedes in the event of a nuclear attack by the Soviet Union. “ (excerpt)
http://www.dailymail.co.uk/news/article-4335302/Sweden-updates-hundreds-nuclear-bunkers.html