High Quality Content by WIKIPEDIA articles! Lockdown (2008) was a professional wrestling pay-per-view (PPV) event produced by Total Nonstop Action Wrestling (TNA), which took place on April 13, 2008 at the Tsongas Arena in Lowell, Massachusetts. It was the fourth annual event under the Lockdown chronology. Eight professional wrestling matches were featured on the event''s card. In the tradition of Lockdown events, every match took place inside a steel structure with six sides, known as Six Sides of Steel.