India, June 16 -- In a striking coincidence reminiscent of Cold War-era symbolism, strategic bombers belonging to the world's two largest nuclear powers crashed within hours of each other on Monday, raising fresh concerns about military aviation safety.

A U.S. Air Force B-52 Stratofortress bomber crashed shortly after takeoff from Edwards Air Force Base in California's Mojave Desert, killing all eight crew members on board. Thousands of miles away, a Russian Tu-22M3 strategic bomber also went down during a training flight in Siberia's Irkutsk region.

The B-52, one of the most recognizable aircraft in the U.S. strategic arsenal, burst into flames moments after leaving the runway during what officials described as a routine test mission. ...