If the Tunguska Event had occurred 50 years and a few hours later it probably would have triggered nuclear war.
At about 7:15 am local time on June 30, 1908, when Tsar Nicholas II ruled Russia, in one of the remotest areas of Siberia, a most unusual event occurred. The few reindeer herders of the local Evenki people who witnessed the event, none from closer than 20 miles away, described seeing a fireball trailing smoke, then a flash brighter than the Sun, followed by a loud noise like thunder. Those closest to the event reported being blown into the air and knocked unconscious, and their dwellings damaged or destroyed. Fortunately, because of the low population density, very few human casualties resulted, but many herds of reindeer perished. Further afield, eyewitnesses reported seeing a large column of smoke rising high into the atmosphere. The asteroid, called a bolide once in the Earth’s atmosphere, with an estimated diameter of 130 feet, had an entry angle of about 30 degrees based on the trail it left in the sky, and exploded at an altitude of about 6 miles. The resultant shock wave and heat blast most likely correlate with the eyewitness reports and with the destruction described by later expeditions. Seismic instruments in Russia hundreds of miles from the site recorded the tremors caused by the shock wave.
...Not until 1927 did Kulik succeed in reaching his goal. Even though 19 years had passed, the area still bore unmistakable signs of the explosion. In his observations on this and three subsequent expeditions, Kulik described a butterfly-shaped area of destruction of 830 square miles with an estimated 80 million trees knocked over.