Cast Iron Split: nice and hot

The Century is a welded steel box. Let the stove cool down and inspect very carefully for a popped weld.

Heat causes metal expansion, which is strong enough sometimes to pop a weld. If a weld popped, it could be a minor issue, like a secondary rack bracket holder, or serious, like the secondary manifold attachment to the shell or an actual seam weld that could cause an air leak. If the parts were slightly bent in fabrication and clamped together to make the weld, then they are under tension. Heat expansion can increase that tension. Welds fail, as have been reported here several times. So far no lightning struck lottery winners reporting in though.

When in doubt it's far better err on the side of caution. Besides, inspecting the interior of a red hot stove singes the eyebrows real quickly.

Probably just coincidence. It a weld is going to fail it's often just a matter of time. The stress of heating and cooling of the metal is the greater influence.

Note that this may not be a weld. It could be another part fit in too tight, like the air wash deflector or it could be a baffle or secondary rack warping or none of the above. Keep us posted.