The state of Maryland has filed a $4 million lawsuit against the federal government over the 2008 crash of a state police helicopter that killed four people.
The state claims in the lawsuit that two air traffic controllers failed to respond adequately to the pilot's distress and contributed to the crash.
The lawsuit accuses the controllers of negligence, saying they didn't provide adequate weather information, didn't help the pilot with his approach in heavy fog and were distracted by less important matters. The controllers are employed by the Federal Aviation Administration.
Attorneys for Jordan Wells, the sole survivor of the crash, filed a similar lawsuit last month that seeks $50 million in damages.
The National Transportation Safety Board concluded that a combination of factors caused the crash.