Regardless of the type of accident you were in, if you were driving a leased vehicle, you should take steps to protect yourself.
First off, at the scene of the accident you should inquire into the well-being of any other drivers after ensuring you have not sustained any major injuries. Afterwards, you should contact the police to come respond to the accident to speak with any witnesses and file an official report. You should speak with the officer and obtain a copy of any report they make.
You are required to exchange your information with any other drivers at the accident scene such as your contact and insurance information. If you can, take photographs of the accident scene and any damage to your vehicle and any bodily harm.