The bridges originally broke in 34 AD, and hadn’t been repaired by 1300. See Dante’s Inferno for details.

Meanwhile, in the Malebolge:

Malpeau: The last bridge is finally finished!

Katzenjammer: Aye! An’ a good strong job she looks like…

…’ere, what’s that light?

Malpeau: Only one thing casts a light that bright–

[RRRRRRUMBLE]

–an envoy from Heaven!

[KRAK]
[KRACK crumble]

Malpeau: Hey! –We just finished rebuilding those!