SACRAMENTO, June 19 — Across the country, the cost of workers' compensation insurance is soaring at the highest rate in nearly a decade, adding yet another heavy burden on businesses and the struggling national economy. The governors of Florida, West Virginia and Washington have called special sessions of their Legislatures this year to find ways to contain costs, and elsewhere, thousands of bills on workers' compensation have been introduced. Advertisement The system covers 127 million workers nationally but is regulated state by state, with no federal oversight. Unlike with Medicare and Medicaid, Congress has no role in the regulation of...