Perhaps someone will correct me if I'm off the mark here, but those firefighting C130s were the old A model and I believe had the original (unmodified) centre wing section.
If so, I'm left wondering why they were still being flown on such duties.
The centre wing (and also outer wings for that matter) of the C130A was a weak design, and has been known as such since the very early years of the C130 after several wing failures in flight. To my knowledge most operators of early C130s all those decades ago modified their centre (and outer) wings when Lockheed came up with a better design. As an aside the Herc finally got the beefy solid wing design it really needed on the C130H.