Stop the source if safe
If you can safely identify and operate the correct shutoff, stopping the incoming water can limit additional damage. Do not take risks around electrical hazards.
Look beyond visible puddles
Water can migrate beneath flooring and into wall cavities. A restoration assessment may include moisture detection in areas that do not look wet at first glance.
Call for local help
Describe where the pipe failed, whether the water source has stopped, and which rooms or materials are affected.