plane, the lockheed aircraft disappeared along with its pilot in 1937. it s believed to be a patch of aluminum that replaced a window on her aircraft during an eight-day stop in miami in that attempt to fly around the world. and there s this, what one writer today called a depressing sign of america s obesity problem, fatter crash test dummies. a company that makes them is developing a new obese version with a body weight of over 270 pounds. the ceo says obese people are more likely to die in a crash because their bodies react differently against restraints in the car. when we come back tonight, one way or another it all ends tonight. we ll take you to kansas city for game seven. .
reporter: it was a spectacular trouble-free flight until this. oh, no, it just crashed. reporter: flying in tight formation in davenport, iowa, this jet suddenly banks for the ground, never recovering. glen smith, a veteran pilot was killed. went nose down into the ground and burst into flames. reporter: since 1988, air show accidents in north america have killed more than 100 pilots and performers. but for the 12 million people who enjoy them every year, air shows are almost always safe. it was a terrible crash in the 50s that led to new rules. planes must now stay 500 to 1,500 feet away from crowds and avoid flying toward people. there hasn t been a spectator fatality since 1962. that s because of the strict rules that have been in place for nearly 60 years. reporter: but there are new rules when it comes to the world of air races after this crash last september.
a p-51 mustang slams into the crowd in nevada. 11 people were killed. federal investigators found the plane had performance modifications that were undocumented and untested. this spring, the ntsb called for stricter rules, more training for pilots, and changes to the racecourse, to better avoid spectators. you re going to see people flying planes to the edge of the envelope, and that means also there s just a bit of assumed risk for any audience member. reporter: for many, a thrill with a risk worth taking. clayton sandell, abc news. clayton, thank you. now to the drama on the shores of new england. more beaches have been closed this labor day weekend due to sharks. this after a lifeless great white shark, 13 feet long washed up along the massachusetts-rhode island border. adding to the anxiety already there after several beach closings this summer. biologists say they don t know why this particular shark died. along the florida coast, two dozen whales came ashore and beach
badly enough to be sent to the hospital. five are still critical. ten died. the p-51 mustang that crashed was 67 years old and heavily modified. we cut ten feet off the wings. reporter: the pilot was 74. veteran stuntman jimmy leeward posted this video on youtube in june. the systems aren t proven yet. we think they re going to be okay. reporter: one possible problem, mechanical failure. in some photos, a thin sliver of of the tail crucial for maintaining balance appears to be missing. another that the pilot blacked out. there is no pilot s head in that cockpit. it tells me that he was likely unconscious slumped over the controls. reporter: federal investigators are also looking at the broader question. how safe was this race to begin with? the pilots of these experimental planes take their lives in their hands. did the spectators know they were doing so, too? pilot john parker is the same age as jimmy leeward and every bit as seasoned. the jimmy leeward
protective fences around the spectator stands. reporter: these are 70-year-old world war ii fighter planes, modified to turn them into drag racers. the airplane looks different. we cut ten feet off the wings, five feet off each side. reporter: in a promotional video, jimmy leeward, the pilot who crashed, described the extensive modifications that made this old propeller plane race as fast as a jet. you need those types of speeds, you need jet speeds. any time you modify an airplane that has been designed for one function, to make it do another function, it makes it less safe. reporter: eyewitnesses say they saw pieces of the plane s tail fall off as it made its final turn. the photos support that. and there s this picture, taken the instant before the crash. there is no pilot s head in that cockpit. that tells me he was likely unconscious, slumped over the controls. reporter: piecing together exactly what happened is now the task of federal investigators. really our m