Thin-foil Faraday collectors mounted near the midplane measure energetic-ion loss signals from the DIII-D tokamak. Modulation of the neutral beam sources shows that, under appropriate conditions, prompt losses from every beam line are observed. Prompt losses are usually larger when the plasma current or toroidal field is low. Enhanced losses occur during ion cyclotron heating. Instabilities that produce strong field perturbations at the edge also produce enhanced losses. © 2010 IAEA, Vienna Printed in the UK & the USA.