Let $\kappa$ be a regular cardinal, and let $\mathbb{P} = Add(\kappa,1)$ be the standard forcing notion for adding a new subset of $\kappa$ using partial function from $\kappa$ to $2$ with domain of size $<\kappa$. This forcing is $\kappa$-closed, so it doesn't collapse cardinals $\leq \kappa$. If we further assume that $2^{<\kappa} = \kappa$ then it is also $\kappa^+$.c.c., so it doesn't collapse cardinals at all.

If we extend the universe and add new bounded subsets of $\kappa$ then $\mathbb{P}$ doesn't stay $\kappa$-closed, but it might still be $\kappa$-distributive. For example it will be the case when we extend the universe by using a $\kappa$.c.c. forcing, by a theorem of Easton.

The only way that I know to force that $\mathbb{P}$ collapses cardinals is by changing the cofinality of $\kappa$. Indeed, if $\mathbb{Q}$ is a forcing such that $V^{\mathbb{Q}} \models\text{cf }\kappa = \omega < \kappa$, then any $V^{\mathbb{Q}}$-generic filter for $\mathbb{P}$ codes an enumeration of all ordinals below $\kappa$ of order type $\omega$ (take $\{\alpha_n \mid n < \omega\}$ a cofinal sequence at $\kappa$. For every $p \in \mathbb{P}$, there is $n < \omega$ such that $\text{supp }p \subseteq \alpha_n$. So we can extend $p$ to a condition $q$ in which the first $\gamma$ coordinates after $\alpha_n$ are zeros and $q(\alpha_n + \gamma) = 1$. By density arguments this defines an enumeration of all $\kappa$).

**Question:** Is it consistent that there is regular cardinal $\kappa$ and a forcing $\mathbb{Q}$ that preserves the regularity of $\kappa$ such that $\Vdash_\mathbb{Q} \check{\mathbb{P}}$ collapses $\kappa$?

**Question:** Is it consistent that for some regular uncountable cardinal $\kappa$ there is no such $\mathbb{Q}$?