The Wall Street Journal reported the information.According to the publication's sources, all preparatory stages for the operation were completed by the end of April, but the launch was delayed until the end of May. Ultimately, the trucks with concealed drones set off on May 23-26. The drivers were not informed about the contents of the cargo.Additionally, as WSJ writes, the operation nearly fell apart at the last moment: while moving, the sliding roof of one of the trucks came off, and the driver, attempting to fix it, discovered the drones inside. He immediately called Artem Timofeev — the owner of the logistics company and coordinator of the operation. Timofeev then contacted the SBU.The head of the Service, Vasyl Maliuk, quickly came up with an explanation that was conveyed to the driver: allegedly the drones were intended for tracking animals in hunting grounds. According to WSJ, the driver accepted this version and did not notice the explosives attached to the unmanned aerial vehicles.On June 1, when the operation started, another problem arose — communication with the cabin of one of the trucks became unstable. SBU employees tried to remotely instruct the driver, but he stopped responding. Later, photos of a dead driver and a burned truck appeared online.The publication noted that the operation coordinator Artem Timofeev was a 37-year-old former DJ who had previously lived in Ukraine but moved to Chelyabinsk in 2018. He participated in the operation together with his wife Kateryna, a tattoo artist.Before the start, both of them were tested on a polygraph, and the couple assembled the drones independently following instructions from Ukrainian specialists.On June 1, Ukraine's Security Service conducted a unique and large-scale operation code-named Spider's Web, which resulted in the destruction of one-third of Russia's strategic aviation; in Russia, this event has already been dubbed the "Russian Pearl Harbor."