A three-dimensional turbulent boundary layer formed when an initially collateral boundary layer encounters transverse wall motion is calculated using a second-moment closure applicable up to a wall. The numerical solutions are extensively compared with an experiment by Lohmann, including the distributions of all the Reynolds stress components. In the inner layer, the turbulence model produces reasonable shear stress components parallel to the wall. This leads to a good prediction of the magnitude and direction of the wall shear stress. In the outer layer, however, a very rapid growth of the transverse shear stress component found in the experiment is not reproduced by the model. A modification of the redistribution model whose effect is limited to the outer layer in developing flows would be desirable.