UFO heard as thunder in Yvelines

Summary

On April 28, 2008, at around 4:10 AM, a witness in Yvelines heard a deep, rolling noise coming from the northeast. The sound evolved into a prolonged thunderclap lasting 5 to 6 seconds, passing over the witness's home and leaving them startled. Afterward, the noise moved away toward the southwest. That day, significant storm activity was indeed recorded in the region, leading the witness to attribute the sound to a thunderclap from a violent storm. Despite the meteorological explanation, the case was classified as "A" by the GEIPAN, indicating that the possibility of an unexplained phenomenon was not ruled out.