In season 4, Bellick's character continues his redemption arc, and he now serves as an almost completely loyal ally to the protagonists. It is revealed in the first episode of season 4 that Sucre, T-Bag and Bellick have all broken out of Sona during a riot which led to the prison burning down.

How did Sucre and Bellick escape from Sona?

Lincoln notifies Michael that Sona has burnt down and Sucre, Bellick, and T-Bag are no where to be seen. It is later on revealed that T-Bag caused the riot which allowed them all to escape. ... With the aid of hitchhiking and Bellick's mom, both Sucre and Bellick managed to flee Panama and arrive back in the US.

Does Brad Bellick escape from Sona?

In both escapes was Brad Bellick used as pion. Here he was used to be captured by the Sona personnel, which made them to the haunted, The Sona Seven. However, he escaped later from Sona.