A four-dipole bunch compressor chicane has recently been installed in the SLAC linac at 9 GeV and is capable of compressing a 3.4-nC electron bunch to an rms length of 50 microns, resulting in a peak current of nearly 10 kA [1]. The electron bunch is extracted from a damping ring with normalized horizontal emittance of similar to 30 mum. We present preliminary measurements of the initial and final emittance in the chicane and compare these to 1D and 3D calculations of the effects of coherent synchrotron radiation (CSR).