accidently, my truck & boat trailer ended up in the willamette river

and a month later the county cops had it pulled out. I went and paid the tow bill, but to get a release so I would not incure further charges with the tow yard, I had to give a statement to the cops. The cop I spoke with, upon my inquiry, told me that I may be facing crimminal charges, federal fines and be required to reimburse the coast guard for their involvement. What can I do? I tried to locate the truck the next day, and I had a diver on hand, but not knowing where to send him to hook up the truck....well I didn't know what to do, until the cops contacted me. then I did what I could, deal with the tow yard. Now what actions can I take to minimize the actions that they may bring against me? It was truely a varifiable accident. And the tow bill wasn't cheap (offset almost 1/3 by scrapping the truck). I work hard, but only part time as I provide care for my handicapped Mom and Dad. And how long is the statue of limitations for such charges to be brought against me? Please, your knowledge and advice will so much be apprieciated. And Thank You for your time.