prove myself. and just seems like you got to prove yourself every year. >> reporter: tonight in seattle dempsey will try to prove himself once again. a man nick named captain america is about to be seen a lot more here. jeff glor, cbs news, new york. >> now to one of the rarest forms of another competition, cliff diving, rare because this version doesn't involve an actual cliff, very tough to find in boston. where these cliff divers instead have been launching themselves off a sort of urban cliff, a tall building. in their 90 foot plunge to the water divers hit speeds up to 60 miles an hour. the two day old panda cub at the national zoo is healthy as can be. vets performed a physical this morning on the still unnamed baby. the animal is skroobed as robust and fully formed with a steady heartbeat. what they don't know yet is whether it's a male or female. one sad note, the mother panda