The S.T.A.R. Labs Particle Accelerator, nicknamed Pipeline by Team Flash, is a device created to accelerate particles. After its explosion, on December 11, 2013, it was shut down and was later repurposed as a prison for rogue Metahumans.
On December 11, 2013, the Particle Accelerator was activated but exploded and released a high amount of Dark Matter across Central City. Among one of those affected was Barry Allen, who gained the connection to the Speed Force and later became the vigilante, The Flash.
After the accident, it was revealed that it caused the death of 17 individuals, unknown injuries and 2600 individuals to gain unnatural powers which became Metahumans.
After defeating Clyde Mardon and Danton Black by killing them, the team realize that killing them is not a suitable way and got the idea of repurposing the Particle Accelerator into a prison as its cavities generates a seal of 100,000 times of the Earth
's magnetic field and is capable of holding Metahumans and Kryptonians. However, it is unable to hold back a Time Wraith and Mitch Romero who had superhuman strength. During Team Flash's vigilante activities, numerous Metahumans were incarcerated here until a Metahuman wing was built in Iron Heights Penitentiary.