[Blitzer:] Kim Jong-Un did not show up at a key ceremony commemorating his father and grandfather. The young North Korean leader was noticeably absent, marking over a month since the ruler of the secretive country with an arsenal of nuclear weapons has been seen. CNN's Brian Todd has been tracking the story for all of us. Brian, what's the latest?
[Brian Todd, Cnn Correspondent:] Wolf, tonight, the anxiety over what's going on inside this regime is heightened. Kim Jong-Un is MIA and his absence from public view resonates all the way to Washington.
[Todd:] A U.S. intelligence official tells CNN it's concerning that Kim Jong-Un is out of sight. The North Korean leader didn't show up at the much-anticipated anniversary of the founding of the ruling Workers' Party. But he did send flowers.
[Gordon Chang, Daily Beast Contributor:] To skip an event which honors your father and your grandfather is a serious breach of protocol unless there's some really good reason. I think right now that Kim Jong-Un is suffering under not only a physical disability but a political one as well.
[Todd:] Is Kim's power eroding? Is he under threat from inside? Senior U.S. officials tell CNN there's no indication Kim has been completely sidelined or is in very bad health. But video showing him limping and recent reports of an ankle or leg injury to Kim only lead to more questions. [On Camera] Why not have him just sitting down behind a desk or behind something to project?
[Jonathan Pollack, Brookings Institution:] Unless he's suffering a severe injury of some sort, I don't think that there should be some intrinsic reason why they don't present him in some kind of a public mode, even if it can't show him walking and being very, very active.
[Todd:] South Korean officials say the regime appears to be operating normally and there are no signs of unusual military activity inside North Korea, often a signal of upheaval. South Korea's Defense minister also says they have reason to believe that Kim Jong-Un is staying at a home near an elite hospital in Pyongyang with his wife and his sister. His younger sister Kim Yo Jong is said to be gaining stature inside the regime. Most analysts downplay rumors that she's in charge while her brother's absent. But if Kim Jong-Un is keeping her close by, could he and his sister be threatened?
[Pollack:] It may not be so much an issue of her personal security and well-being, so much as it is he's got to have some kind of a reliable channel near him.
[Todd:] But adding to the tension, an exchange of gunfire across the border, when South Korean activists released these balloons filled with anti-North Korean literature, North Korean gunners fired at them. South Korea responded with its own machine gun rounds. There were no injuries in that incident. But it was the second exchange of fire between the two sides this week after a confrontation at sea. Now analysts say the longer Kim Jong-Un's public absence continues, the more worrisome it is for South Korea, Japan and the U.S. This is a dangerous regime with nuclear, chemical, biological weapons, long-range missiles. And right now, no one's sure who's running the place Wolf.
[Blitzer:] Let's not forget there are nearly 30,000 U.S. troops on that border between South and North Korea.
[Todd:] That's right.
[Blitzer:] Along the demilitarized zone.
[Todd:] So much potential danger.
[Blitzer:] As well. All right. Brian, thanks very much. Just ahead, police seized the taxi cab driven by the suspect Jesse Matthew as the search for the missing University of Virginia student Hannah Graham expands. We're going to bring you the latest.