$西北天然气(NWN)$ 8-K - Current report Filed: 2015-06-24 AccNo: 0000073020-15-000018 Size: 171 KBItem 5.02: Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers: Compensatory Arrangements of Certain OfficersItem 9.01: Financial Statements and Exhib 网页链接