Unscored loaf is sealing up
An unescorted loaf of bread, in a loaf pan, generally bursts along the top of the loaf pan.  If you want a "burst" look you need to score the area you want a burst using a razor blade or sharp knife.

Are you making a no-knead loaf in a Dutch oven?  They generally burst along the shaggy seams.

Rob is right, scoring and bread turning into a brick are not really related.