The first ten minutes matter. This is a short checklist for the things that actually help, and the things that make it worse.
If you smell burning
A hot plastic or fishy smell near a wall, an outlet or the panel is an overheating connection. Switch off the breaker for that area if you can identify it, or the main if you cannot and you can reach it safely.
Do not open the panel. Do not spray water on anything. Move people away from the area and call (888) 633-7804 with a description of where the smell is strongest.
If an outlet is sparking or scorched
A small blue flash as a plug goes in is normal. Sustained sparking, smoke, or a brown scorch mark around the slots is not. Switch off that circuit at the panel and leave everything unplugged.
Do not plug anything else into it to test whether it still works.
If the power is out
Check whether neighbours have power. If the whole street is dark, it is a utility outage and the utility is already working on it. If only your property is affected, check the main breaker and any outdoor disconnect.
If half the house is out and the other half is fine, that often points to a lost leg at the service. It should be looked at rather than left, because it can put uneven voltage on your appliances.
If someone has had a shock
Do not touch the person while they are still in contact with the source. Kill the power at the breaker or main first. Then seek medical attention, even if they feel fine, because electrical injuries can have delayed effects.
After that, treat the circuit as faulty and leave it off until it has been tested.
If water has reached electrical equipment
Do not enter standing water in a room where outlets or equipment are submerged. Switch off at the main from a dry position if you can do so safely, and if you cannot, stay out and call.
Flooded panels, breakers and outlets are replaced rather than dried out. Contamination inside the device does not leave when the water does.
What to have ready when you call
Your address and the nearest cross street, what you saw or smelled, which breakers you have already switched off, and whether anyone is without power for medical equipment. That last one changes how we prioritise dispatch.