Calculating Damage for the Fling Action

DND 5e. Among my group there seem to be multiple ways of interpreting the damage from the action “Fling”.

From the Kraken:

Fling. One Large or smaller object held or creature grappled by the kraken is thrown up to 60 feet in a random direction and knocked prone. If a thrown target strikes a solid surface, the target takes 3 (1d6) bludgeoning damage for every 10 feet it was thrown. If the target is thrown at another creature, that creature must succeed on a DC 18 Dexterity saving throw or take the same damage and be knocked prone.

The distance for the damage calculated is in question:

If the creature is thrown an intended 60ft but interrupted say 30ft in by a solid surface, is the distance then considered to only be 30ft for the damage calculation? This would seem to be supported by the “up to 60ft” phrasing, but also would then imply that the creature thrown had less momentum from an interpretation of physics simply due to a wall existing in the way.

Or would the damage be considered from the full 60ft of the initial throw? The “up to 60ft” would assert an individual could be thrown less distance by the kraken’s intent, randomly, DM, etc. Then, the damage in question could be based on this.

The interpretation of the “up to” is up to DM discretion. For damage which of these is correct?