As for the situation you mentioned, from a superstitious point of view, rain coming out of the grave may be regarded as an unlucky sign. However, this view lacks scientific basis and cannot represent any real events or information.
I suggest to understand and treat this situation from a rational point of view. Rain is a natural phenomenon, which may happen at any time, and has nothing to do with artificial burial. However, the accumulation of water in the grave may be caused by factors such as high soil water content or high groundwater level, which does not mean that there are any supernatural events.
In the face of such difficult times, we should face life with a rational, scientific and positive attitude. Keep your heart calm and strong, and believe that everything will be fine.