Authorities in suburban Milwaukee say several coal train cars have derailed but there is no threat to public safety. West Allis Police Chief Patrick Mitchell said at a news conference that the derailment occurred early Thursday evening. He says two workers were on the train at the time and neither was injured. The cause of the derailment is under investigation. Mitchell says police believe 16 of the train's 147 cars jumped the tracks at various points. City Fire Chief Mason Pooler added that coal spilled from some cars in two spots.