Lots of stuff happened in 1999 in the Classic World of Darkness. (Here's a link to the timeline.) We're specifically concerned with July 4th.
The Technocracy implement Operation Ragnarok.They use neutron missiles and four reflecting orbital mirrors to reduce the Ravnos Antediluvian to dust. Simultaneously, Technocrat Xerxes Jones detonates a nuclear device in the Labyrinth at the mouth of Oblivion, while the forces of Stygia drop a relic nuke on Enoch. So much spirit energy releases the Sixth Great Maelstrom and starts the Avatar Storm.
Why was Xerxes Jones doing this experiment? He had infiltrated the Orphic Circle.
Xerxes Jones, a Void Engineer who had infiltrated the Orphic Circle, was provided with the materials to build his Spirit Nuke by the cult. The cult (aware of his experiment) was expecting a full report from him when he returned. Jones's nuke was set off prematurely by the detonation of the relics of the nuclear weapons Fat Man and Little Boy, which were released by relic bombers of the wraithly Hierarchy in the assault of Enoch, the fortress of the Black Hand. The combined effect resulted in the Sixth Great Maelstrom, the awakening of Grandmother, and the creation of the Stormwall. Thus, Jones's “experiment” resulted in the destruction of the cult's headquarters and most of its members. Only two helicopters containing several of the Circle's leaders managed to flee the stronghold in the face of the Spectral onslaught.
I couldn't find any notes on why Jones' supervisors in the Technocracy weren't aware of his experiment happening at this time. They may have been too distracted by the battle with Ravnos or they may have not wanted Jones to blow his cover. Suffice it to say, I don't think that the Technocracy or the Orphic Circle had any idea what would happen, even if the experiment went as planned. (Which it decidedly did NOT.)