Emergency water removal
The first hours decide how much of the job is drying and how much is rebuilding. Materials that are wet for a few hours usually recover. Materials that are wet overnight often do not.
Before anyone arrives
Stop the source if you can reach it safely — the fixture shut-off, or the main on the street side of the foundation wall. Move what can be lifted out of the water, starting with anything porous or irreplaceable. Photograph everything before it moves, for the claim.
When to stay out of the room
Standing water anywhere near a panel, a furnace, a boiler or an outlet is an electrical hazard. In most Maryland basements the panel is mounted on the wall the water reaches first, because that is where the service enters. If the circuit cannot be shut off from a dry location, treat the room as unsafe.
Water that came from a sewer or from outside should not be walked through without protection, whatever it looks like.
What the clock is doing
Drywall wicks moisture upward within minutes and keeps going. Carpet padding holds many times its weight in water and passes it into the subfloor. In a closed Maryland basement in July, humidity climbs fast enough that growth can begin within a couple of days — which is why extraction and air movement start immediately rather than after the assessment is finished.