A hospital district in Pilot Knob, Mo., filed for municipal bankruptcy protection from its creditors yesterday, Bloomberg News reported. The Iron County Hospital District, which owns a local hospital, listed liabilities between $10 and $50 million and assets between $1 million and $10 million. The district has about $6.5 million in bonds outstanding, said Daniel Doyle, a lawyer at Lashly & Baer who is representing the district.