  We study the bounded fundamental class in the top dimensional bounded
cohomology of negatively curved manifolds with infinite volume. We prove that
the bounded fundamental class of $M$ vanishes if $M$ is geometrically finite.
Furthermore, when $M$ is a $\mathbb{R}$-rank one locally symmetric space, we
show that the bounded fundamental class of $M$ vanishes if and only if the
Riemannian volume form on $M$ is the differential of a bounded differential
form on $M$.
