PROVIDENCE, R.I. (AP) — Rhode Island is the nation's smallest state. But its pension problem may well be the largest in the land.

The state is on the hook for billions of dollars' worth of pension benefits owed to police officers, firefighters, teachers, judges and state workers. But the money's not there. Projected investment gains never happened. State actuarial projections failed to keep up with public workers who are retiring earlier and living longer.

Estimates put Rhode Island's unfunded liability for public workers' pensions at $7 billion, slightly less than the entire state budget for one year. To make good on promises to public workers, the state must pour more and more into the pension system every year, from $319 million in 2011 to $765 million in 2015 and $1.3 billion in 2028.