This picture taken on November 23, 2010 by a South Korean tourist shows huge plumes of smoke rising from Yeonpyeong island in the disputed waters of the Yellow Sea on November 23, 2010. North Korea fired dozens of artillery shells onto a South Korean island on November 23, 2010, killing four people, setting homes ablaze and triggering an exchange of fire as the South's military went on top alert. (STR/AFP/Getty Images)  

 A picture of smoke rising at Yeonpyeong Island after it was hit by dozens of artillery shells fired by North Korea, is shown on a mobile phone of a resident of the island November 23, 2010. (REUTERS/Kyodo) #

 A resident attempts to extinguish a house fire during North Korea's artillery shelling of Yeonpyeong Island November 24, 2010. (REUTERS/Yonhap)

 Smoke billows from a brushfire on a mountain on Yeonpyeong Island, South Korea, Wednesday, Nov. 24, 2010. (AP Photo/Yonhap)

 Fire fighters extinguish a fire on Yeonpyeong island in the disputed waters of the Yellow Sea on November 24, 2010 after North Korea fired dozens of artillery shells the day before. (Incheon Fire and Safety/AFP/Getty Images)

 Smoke billows from multiple locations on Yeonpyeong island near the border between North Korea and South Korea on Tuesday, Nov. 23, 2010. (AP Photo/Yonhap) KOREA OUT

 Destroyed houses are seen on Yeonpyeong Island, South Korea, following artillery exchange between North and South Korea on November 24, 2010. (Korea Pool/Getty Images)

 An aerial view shows destroyed houses on Yeonpyeong island, South Korea, Wednesday, Nov. 24, 2010, one day after North Korea's artillery attack on the island. (AP Photo/Yonhap, Kim Hyun-tae)

 This handout picture taken and released on November 24, 2010 by the Ongjin County Office shows the badly damaged interior of a house on Yeonpyeong island in the disputed waters of the Yellow Sea a day after North Korea fired dozens of artillery shells. (Ongjin County office/AFP/Getty Images)

 Destroyed houses on Yeonpyeong island in the disputed waters of the Yellow Sea after North Korea fired artillery shells at the island, seen on November 23, 2010. (Ongjin County office/AFP/Getty Images)

 Residents are seen at an air-raid shelter after being evacuated in Yeonpyeong Island following an artillery attack by North Korea November 23, 2010. (REUTERS/Ongjin County)

 A shell fired from North Korea is seen on Yeonpyeong Island November 24, 2010. (REUTERS/Park Jong-Sik/Hankyoreh)

 Residents wait to get aboard a ship before they leave Yeonpyeong island November 24, 2010. (REUTERS/Park Jong-Sik/Hankyoreh)

 South Koreans take a moment of silence for South Korean marines killed in a North Korean bombardment during a rally against North Korea's recent attack, in Seoul, South Korea, Tuesday, Nov. 23, 2010. (AP Photo/Ahn Young-joon)

 South Koreans read extra edition newspapers in downtown Seoul on November 23, 2010 after North Korea earlier in the day fired dozens of artillery shells onto a South Korean island. (KIM JAE-HWAN/AFP/Getty Images)

 Members of the South Korean Coast Guard evacuate residents from Yeonpyeong island in the disputed waters of the Yellow Sea after North Korea fired dozens of artillery shells the day before, on November 24, 2010. (Korea Coast Guard/AFP/Getty Images)

 South Korean survivors arrive as they are surrounded by relatives and media at a port in Incheon, west of Seoul, South Korea, Wednesday, Nov. 24, 2010. (AP Photo/ Lee Jin-man)

 Survivors of the artillery exchange between North and South Korea arrive at Incheon port from Yeonpyeong Island on November 24, 2010 in Incheon, South Korea. (Chung Sung-Jun/Getty Images)

 Members of the media interview local residents from Yeonpyeong island as they arrive at the port in Inchon, west of Seoul, on a police vessel on November 24, 2010. (KIM JAE-HWAN/AFP/Getty Images)