Multiple reports say a US military training exercise involving an experimental electronic warfare activity is being linked to the crash of a medical plane that kills four Americans. The outlets describe the incident as the first known civilian deaths in the United States connected to electronic warfare, highlighting that the victims were on board a civilian medical aircraft rather than a military plane. The reporting attributes responsibility to the US military training exercise, describing it as a factor that contributed to the crash. However, the articles do not provide additional verified technical details, such as the exact nature of the weapon test, the sequence of events leading to the crash, or findings from an official investigation. The accounts also do not specify the identities of the victims or the precise location and date of the crash in the provided text. Overall, the sources converge on the core claims: a medical plane crashes, four Americans die, and investigators or authorities associate the incident with a US military electronic warfare training activity.