We investigate the dynamical effects of rapid gas expulsion from the core of a young stellar cluster .
The aims of this study are to determine 1 ) whether a mass-segregated core survives the gas expulsion and 2 ) the probable location of any massive stars that have escaped from the core .
Feedback from massive stars is expected to remove the gas from the core of the cluster first , as that is where most massive stars are located .
We find that gas expulsion has little effect on the core for a core star formation efficiency , \epsilon , of greater than 50 % .
For lower values of \epsilon down to 20 % , a reduced core survives containing the majority of the massive stars while some of them are dispersed into the rest of the cluster .
In fact we find that ejected stars migrate from radial to tangential orbits due to stellar encounters once they leave the core .
Thus , the location of massive stars outside of the core does not exclude their forming in the dense cluster core .
Few massive stars are expected to remain in the core for \epsilon lower than 20 % .