It describes a UFO crash in 1945 next to the Trinity test site in New Mexico, just 20 days after the first ever atomic bomb test on United States soil occurred there.
And in fact, the Trinity test site in New Mexico, there was a test on July of 1945, and then 20 days later in San Antonio, you see this crash.
Trinity is a fascinating story, just 20 days after the first atomic test on US soil, and two days after the Japanese concession, a metallic avocado shaped object dropped from the sky in San Antonio, New Mexico right next to the test site.