We report on high intensity single-shot laser ablation of monocrystalline silicon with a nanosecond Nd:YAG at 355 nm. It is shown that for incident laser intensities exceeding similar to 11.5 GW/cm(2) on the silicon surface, unusually high etch depths can be achieved reaching values up to 60 mu m. The results support previous observations of dramatic increase in etch rates in single-shot laser ablation at 266 nm. A laser-induced explosive boiling mechanism together with secondary plasma heating is believed to be associated with this effect. (c) 2005 Elsevier B.V. All rights reserved.