Emergency Manager Kevyn Orr outlined a plan for creditors Friday to stop Detroit’s downward spiral by spending $1.25 billion on public safety and other city services, money that could come from slashing the city’s $17 million in debt. Orr unveiled the historic proposal during a closed-door meeting with about 150 representatives from banks, bondholders, unions and pension funds, all of whom were asked Friday to make steep concessions. The unprecedented plan — including sweeping changes to pension and health care benefits — is seen as the first step in negotiations toward what could be the biggest municipal bankruptcy filing in U.S. history.