If you are driving a trailer with a blown tire, there are several risks involved. First of all, if the tire blowout is severe enough, it could cause the trailer to jackknife. This means that the trailer will swing out to the side, potentially causing serious damage to your vehicle and anyone nearby. Secondly, even if the tire doesn't cause the trailer to jackknife, it could still come detached from the vehicle entirely. This would not only create a hazard for other drivers on the road, but could also result in your losing control of your vehicle completely. Finally, if you do manage to keep control of your vehicle and don't crash or cause an accident, you will still likely have to pay for damages to your trailer and any contents that may have been lost or damaged in the process.