Saturn square Uranus, with Mars forming a difficult aspect (conjunction, square, or opposition) to one or both of these planets has often coincided with turbulent weather events (e.g., tornadoes), and an uptick in accidents (e.g., airplane crashes, explosions), major earthquakes, and man-made as well as natural disasters.
I don’t believe there is a causative effect (as in planetary alignments do not cause these events to happen), but there appears to be a correlation. There is an increase in certain types of stressful events during difficult planetary transits. The embedded video goes through some examples of the events that took place specifically under tense transits between Saturn and Uranus, when also triggered by Mars, in 1953, 1975-76, 1988, 2000, 2010, and 2021.
In 2021, Saturn, Uranus, and Mars will form a T-Square in late June to early July (approx. June 29 – July 9, 2021). Saturn will oppose Mars, and both Mars and Saturn will square Uranus.
Besides Saturn/Uranus combinations, there are other planetary transits that often correspond to accidents/disasters/quakes/etc. For example, alignments of slow-moving planets with Moon Nodes and/or in aspect to Chiron. Also, when Jupiter gets “involved,” the magnitude of the event is typically larger in scale or impact. Pluto transits appear to increase death toll or coincide with things that occur “underground,” such as mining incidents.
During major events, such as a large earthquake or a large-scale industrial disaster, the event charts often have slow-moving planets (e.g., Saturn or Pluto) on one of the axis of the chart (e.g., Ascendant or IC). For instance, Uranus was rising in the Chernobyl Explosion chart [to clarify, this is not one of the events in the video, am just mentioning it as an example of a slow planet on an axis on an accident chart].
This chart and other interesting info, including a collection of mundane charts for various accidents, can be found on http://www.astro.com: