If you find someone

Secure the location

Secure the location where the accident took place so that you don't put yourself in danger (hanging wires, pieces of glass, etc.).

Check consciousness

Talk with them, shake them, see if they respond to pain (pinch the underside of the upper arm

Check breathing

Watch their breathing: if necessary, clean out the roof of their mouth. Pull their head back to make sure that the airways are clear. Bend over the person and check the following: chest is rising and falling, sound of breathing, breath on your cheeks.

If the person is breathing, but not conscious --> see First Aid for someone unconscious

If the person isn't conscious or breathing --> see First Aid for someone not breathing/heart not pumping

Check breathing

-WHERE did it happen?

-WHAT happened?

-HOW MANY people are affected?

-WHAT INJURIES does the affected person has?

-WAIT for queries.

You only have to describe the symptoms and not mention that drugs are involved, to avoid that police will come to the site aswell.