If you discover an incident
If you disturb someone who has broken in or entered by other unauthorised means DO NOT confront them, especially if you are alone.
Use the nearest telephone - dial '999'. By doing this you will get a fast response. Try to get a description of the offender. Are there any accomplices? If a vehicle is used the registration number, or part of it, the type of vehicle and colour will be of great help. Which direction did either persons or vehicle go?
After the event
If you arrive at your building and find there has been a break-in, telephone your nearest Police Station (you should have these details to hand). Do nothing else until an Officer arrives - preserve the scene. The first Police Officer to arrive will advise you on what to do. Remember - do not touch or clean anything - preserve the scene of the crime.
You should also contact your insurance company at this time since they may be able to help you with the recovery.