Shuffling off this mortal coil out in the open is not good since there tends to be a large number of organisms around to take advantage of such events to reduce your remains and FP quite rapidly. Similarly your FP can be badly affected if you are rolled around by storms. This cuts down the possibility of further contributing to the food chain and in certain instances provides an environment suitable for preservation. This covers the survival of the organism's remains after death and its transition into a fossil. Burial is the premier method of ensuring passage into the preservation stage.
Rapid burial is a common process which occurs on a regular basis.
Floods, storms, landslides, and volcanic ash eruptions lay down sediments over a period of hours to days. In some cases several meters of sediment can be dumped in near-shore environments by severe storms. Sedimentation does not have to occur on a slow, steady, incremental basis. Rapid sedimentation is part and parcel of current geological theories and is an important causal constituent of the rock record. However, not all environments are preserved equally in the rock record, leading to a heavy bias towards shallow, near-shore marine environments.