While every case is different, you will need (at a minimum) the following:
* photos of the scene, ideally photos depicting the condition
* as many witnesses to the incident, or the dangerous condition, as you can find (remember, you yourself are also a witness)
* the “incident report” (if it occurred in a business establishment)
* proof of your injuries and damages; and
* reports of prior incidents (if they exist).
Many cases will also require bringing in an expert witness, especially if the dangerous or hazardous condition is not apparent (as in a slick surface), who can evaluate the condition and testify as to what caused you to fall, based on his/her technical education, training or experience. If you work with an injury attorney, he or she will have the necessary resources at hand to prove your case.