(CNN) -- North Korean leader Kim Jong Il is dead, North Korean state TV said Monday.
Kim, 69, died at 8:30 a.m. Saturday, state TV said.
A broadcaster reported that Kim died due to "overwork" after "dedicating his life to the people."
Kim died of "great mental and physical strain" while in a train during a "field guidance tour," North Korea's state-run KCNA news agency reported.
A look back at the life of Kim Jong Il
More specifically, the agency noted that Kim suffered a heart attack and couldn't be saved despite the use of "every possible first-aid measure."
He had been treated for "cardiac and cerebrovascular diseases for a long period," KCNA noted.
South Korea's military declared an "emergency alert" following Kim's death, according to South Korean news agency Yonhap. North Korean and communist party officials "released a notice on Saturday informing" members of the Workers' Party of Korea, military "and all other people" of Kim's passing, according to KCNA.
The son of Kim Il Song, the founder of the communist nation, Kim Jong Il had been in power since 1994 when his father died of a heart attack at age 82.
The enigmatic leader was a frequent thorn in the side of neighboring South Korea, as well as the United States. There have been reports in recent years about his health, as well as that power will be transitioned to his son, Kim Jong Un.
North Korea's nuclear program -- and international attempts to hinder its nuclear weaponry potential -- put Kim at odds with many world leaders in recent years, as did his governing style.
Under his leadership, North Korea was largely closed off to outside influences, fearful of threats from its neighbors and subject to decades of political socialization. At the same time, it also sought international aid after extensive famines that contributed to the deaths of tens of thousands of people.
North Korean news reports earlier this fall indicated that Kim Jong Il had been traveling around the country and visiting China, a big change from 2009 when he was thought to be ill with cancer.
Two senior U.S. military officials said then that they believed the pace of North Korea's planned regime change from Kim to his 20-something son appeared to have slowed.
The son, also known as Kim, started his career as a four-star general and in recent years was given more official duties by his father.
CNN's Wolf Blitzer, who traveled to Pyongyang a year ago with former U.S. ambassador Bill Richardson, said that "the assumption (then) was that he was sick" but still in "decent shape."
Now it is a "totally uncertain situation," Blitzer said.
North Korean leader Kim Jong Dies
Kim, 69, died at 8:30 a.m. Saturday, state TV said.
A broadcaster reported that Kim died due to "overwork" after "dedicating his life to the people."
Kim died of "great mental and physical strain" while in a train during a "field guidance tour," North Korea's state-run KCNA news agency reported.
A look back at the life of Kim Jong Il
More specifically, the agency noted that Kim suffered a heart attack and couldn't be saved despite the use of "every possible first-aid measure."
He had been treated for "cardiac and cerebrovascular diseases for a long period," KCNA noted.
South Korea's military declared an "emergency alert" following Kim's death, according to South Korean news agency Yonhap. North Korean and communist party officials "released a notice on Saturday informing" members of the Workers' Party of Korea, military "and all other people" of Kim's passing, according to KCNA.
The son of Kim Il Song, the founder of the communist nation, Kim Jong Il had been in power since 1994 when his father died of a heart attack at age 82.
The enigmatic leader was a frequent thorn in the side of neighboring South Korea, as well as the United States. There have been reports in recent years about his health, as well as that power will be transitioned to his son, Kim Jong Un.
North Korea's nuclear program -- and international attempts to hinder its nuclear weaponry potential -- put Kim at odds with many world leaders in recent years, as did his governing style.
Under his leadership, North Korea was largely closed off to outside influences, fearful of threats from its neighbors and subject to decades of political socialization. At the same time, it also sought international aid after extensive famines that contributed to the deaths of tens of thousands of people.
North Korean news reports earlier this fall indicated that Kim Jong Il had been traveling around the country and visiting China, a big change from 2009 when he was thought to be ill with cancer.
Two senior U.S. military officials said then that they believed the pace of North Korea's planned regime change from Kim to his 20-something son appeared to have slowed.
The son, also known as Kim, started his career as a four-star general and in recent years was given more official duties by his father.
CNN's Wolf Blitzer, who traveled to Pyongyang a year ago with former U.S. ambassador Bill Richardson, said that "the assumption (then) was that he was sick" but still in "decent shape."
Now it is a "totally uncertain situation," Blitzer said.
North Korean leader Kim Jong Dies
