What happens if I get into an accident and don't have insurance?

As my brother Attorney above stated you need to get a copy of the police report.

If there was damage exceeding $1,000.00 to either vehicle this accident needs to be reported to the Registry of Motor Vehicles and a "Motor Vehicle Crash Operator Report" should be filed within 5 days. Furthermore, you should never fail to exchange some basic information such as, Name, address and contact details, driver license number, license plate number of the vehicles involved, and auto insurance information or lack of auto insurance. You should Speak to a lawyer in regard to this issue. IF you would like to give me a call I would be happy to speak with you about this matter. 517-505-1464

If you have no insurance, then the person whose car you damages can go after you.  If you are a Mass. resident, the police can file criminal charges against you for driving uninsured.

speak to a lawyer ASAP.

The accident report should have all the information you need on it and you should file for a copy as soon as possible. 

As for what to do about the damage, if you have no insurace that covers property damage you may be out of luck.  As for the other car, it depends on the type of insurance they have to cover their own damage.  Then there comnes the assessment of liabaility and who may go after whom for payment.  You might want to seek some advice on this from an attorney in your area just to anticipate the worst.  Good luck.