(CNN) -- A blowout preventer that may hold important forensic evidence as to why it failed, triggering the world's largest accidental oil spill, has been brought to the surface of the Gulf and placed on a vessel, officials said Saturday night.
The device "was taken into custody by the U.S. Department of Justice as evidence in its ongoing investigation into the incident," BP said. The blowout preventer was lifted to the surface at 8:53 p.m. (9:53 p.m. ET).
Adm. Thad Allen, the government's national incident commander, said the huge blowout preventer "is considered evidentiary material".
The April 20 explosion killed 11 workers aboard the Deepwater Horizon rig.
A new blowout preventer was installed atop BP's plugged well late Friday.
Crews had to flush out potential hydrates -- crystals that form in cold temperatures -- before the old blowout preventer was hauled about the Q4000 surface vessel.
CNN
