...Detailed Information regarding this incident:
retrieved from wikipedia
08:20: North sends a telex message requesting a halt to the South's artillery training exercise.
10:00: South starts the artillery training exercise.
14:34: North starts firing shells (around 150, of which about 60 land on Yeonpyeong)
14:38: South conducts emergency sorties with two KF-16 fighters.
14:40: South deploys four F-15K fighters.
14:46: South conducts another emergency sortie with two KF-16 fighters.
14:47: South fires back with the first round of K-9 howitzers (50 shells).
14:50: The highest alert (Alert Jindotgae Hana) ever given for a local provocation is issued.
14:55: North stops firing temporarily.
15:12: North starts firing for the second time (20 shells, all of which landed on the island).
15:25: South resumes firing back with K-9 howitzers (30 shells).
15:30: South telexes the North's military general level talk representative requesting an immediate halt to artillery shelling.
15:40 – 16:00: The South's Joint Chiefs of Staff Han Min-gu and USFK Commander Walter L. Sharp have a video conference (a review of cooperative crisis management).
15:41: North stops firing.
16:30: First military casualty reported.
16:35 – 21:50: Foreign and National Security representatives have a meeting.
16:42: South stops firing.
18:40: Lee Hong-gi, the South's Joint Chief of Staff Director of Operations, holds a press briefing.
20:35 – 21:10: South Korean President Lee Myung-bak meets with his Joint Chief of Staff.[16][21]
South Korea artillery positions on these islands firing west would actually drop shells in undisputed North Korean territory. The South Korean artillery would have to fire south west to avoid North Korean territory.
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