Near Earth Objects (NEOs) are asteroids or comets whose perihelion distance is less than 1.3 AU. Current estimates suggest that large NEOs (diameter 140m or more) impact the earth every few thousand years on average. Smaller asteroids (30m-50m) are believed to impact the earth with an average frequency of ~100 years, but this estimate is highly uncertain, based in part on an incomplete understanding of the size distribution of NEOs below 100m. Until now, it has not been possible to measure the size distribution of these objects, because large-aperture telescopes have not been equipped with very wide-field imagers. Now, the large étendue of DECam+Blanco allows us to probe a previously unexplored region of NEO parameter space and therefore hazard space. We have recently initiated a 30-night survey with DECam, with the goal to measure the size distribution of NEOs below 100m. Here we report on preliminary results based on the first 10 nights of our survey.