  We present 75As nuclear magnetic resonance data in the paramagnetic and
magnetic states of single crystal CaFe2As2. The electric field gradient and the
internal magnetic field at the As sites change discontinuously below the first
order structural transition at T0 = 169 K. In the magnetic state, we find a
single value of the internal hyperfine field consistent with commensurate
antiferromagnetic order of Fe moments pointing in the ab plane. The spin
lattice relaxation rate shows Korringa behavior for T<T0/3, reflecting the
metallic nature of the ordered state. Surprisingly, 1/T1 exhibits a small peak
at 10 K, revealing the presence of slow spin fluctuations that may be
associated with domain wall motion.
