You are stacking shelves in the home goods area of the store where you work when you hear a loud crash and the sound of glass shattering. As a trained first aid provider, you cautiously move to see what happened. A frightened-looking customer is sitting on the floor next to a display that has collapsed. She is surrounded by broken glass. You carefully get to her and let her know you are trained and can help. She appears aware of what has happened and is breathing normally. You scan the floor around her and see a growing pool of blood behind her. The back of her blouse is soaked with blood. What do you do next?

Observe the situation up close, if it is safe to approach the person without hurting yourself do so. If it is unsafe for you to approach leave immediately and get help. Don't attempt a situation that will have a worse outcome for two lives instead of one.
Familiarize yourself with the person. Exchange names and let them know that you are a trained first aid provider and that you are there to help them. Make a conversation with the individual if possible to find out what happened and if they have any underlying conditions. This may help EMS if they lose consciousness later.
Since you see that there is a pool of blood behind her, try to stop the bleeding. Usually this means applying pressure to the wound. You may first need to observe the wound carefully as debris and objects may be stopping it from being worse. If it is an extremity and pressure cannot be applied then it is best to elevate the wound above the head and chest level. Try to keep the individual calm. Check to see the extent of the bleeding to see if it is causing the skin to be pale or sallow.
After the patient is stabilized as best as you can CALL FOR HELP! Give as many details about the situation as you know. If possible follow up or make yourself available for contacts. Patient may want to extend gratitude.