of the heart, upsetting normal operations. This effect might explain cases where cardiac arrest or seizures followed a lightning strike that produced no external injuries. It may also point to the victim not being directly struck at all, but just being very close to the strike termination. Another effect of lightning on bystanders is to their hearing. The resulting shock wave of thunder can damage the ears. Also, electrical interference to telephones or headphones may result in damaging acoustic noise. Epidemiology There are about 240,000 lightning strikes incidents around the world each year. According to National Geographic, about 2,000 people are killed annually worldwide by lightning. If all eight billion humans have an equal chance of being killed over a 70-year lifespan, this gives a lifetime probability of about 1 in 60,000. However, due to increased awareness and improved lightning conductors and protection, the number of annual lightning deaths has been decreasing steadily year by year. According to the National Oceanic and Atmospheric Administration, over the twenty years to 2012 the United States averaged 51 annual lightning strike fatalities, making it the second-most frequent cause of weather-related death after floods. In the US, between 9 and 10% of those struck die, with an annual average of 25 deaths in the 2010s decade (16 in 2017). In the United States in the period 2009 to 2018 an average of 27 lightning fatalities occurred per year. In the United States an average of 23 people died from lightning per year from 2012 to 2021. It was also reported that some people receive lifelong brain injuries. In Kisii in western Kenya, some 30 people die each year from lightning strikes. Kisii's high rate of lightning fatalities occurs because of the frequency of thunderstorms and because many of the area's structures have metal roofs. These statistics do not reflect the difference between direct strikes, where the victim was part of the lightning pathway, indirect effects of being close to the termination point, such as ground currents, and resultant, where the casualty arose from subsequent events, such as fires or explosions. Even the most knowledgeable first responders may not recognize a lightning-related injury, let alone particulars, which a medical examiner, police investigator, or on the rare occasion a trained lightning expert may have difficulty identifying to record accurately. Direct-strike casualties could be much higher than reported numbers. It has been reported that "30-60 people are