  Deep 21-cm HI line observations of the Virgo cluster spiral galaxy NGC 4569
have been obtained with the VLA in its D configuration and with the Effelsberg
100-m telescope. A low surface density arm was discovered in the west of the
galaxy, whose velocity field is distinct from that of the overall disk
rotation. The observed gas distribution, velocity field, and velocity
dispersion are compared to snapshots of dynamical simulations that include the
effects of ram pressure. Two different scenarios were explored: (i) ongoing
stripping and (ii) a major stripping event that took place about 300 Myr ago.
It is concluded that only the post-stripping scenario can reproduce the main
observed characteristics of NGC 4569. It is not possible to determine if the
gas disk of NGC 4569 had already been truncated before it underwent the ram
pressure event that lead to its observed HI deficiency.
