The dynamics of single drop impact on a liquid pool have been studied in various sizes of drop, velocity and direction of impact. It is generally conceived that a hemispherical crater is created on the surface of the liquid when a high speed drop collides with the pool. Here we examine the case that drops collide successively on the crater induced by previous drops. For a few microsecond after the impact of the first drop, continuous impacts of drops make a deep crater whose depth is hundreds times deeper than that of the impacting drop and we call it “elongated crater”. When the elapsed time after the impact of the first drop approaches a certain value, the elongated crater collapses and the surface of the liquid forms the shape of cusp. The cusp maintains its shape and depth although the drops keep impacting on the cusp. Here we visualize the behavior of elongated crater and cusp with a high speed camera and analyze their features by scaling analysis.