May be $\pi:Y \mapsto X$ a general fibred manifold. Is it true that in fibred manifold a connection always exists? This wiki article states this: https://en.wikipedia.org/wiki/Connection_(fibred_manifold)
Connection is an additional structure on a manifold and the manifold has to be smooth as a requirement that a connection exists. Or can connections be defined also in non-smooth manifolds? Which manifolds have neither a metric nor a connection (any examples?)?