(Newser) – A golf course is apologizing for advertising nine holes of golf for $9.11 on the anniversary of the Sept. 11, 2001, terrorist attacks. Tumbledown Trails Golf Course in Wisconsin advertised the special with an ad yesterday saying it was meant to commemorate the 12th anniversary of the attacks that killed nearly 3,000 people. (See the ad, complete with exclamation points, here.) News of the special spread on social media, and the golf course's Facebook page was overrun with negative comments.

The golf course has since apologized on Facebook and said it may close Sept. 11 out of concerns for the safety of its staff: People are calling the club with death threats, according to owner Marc Watts. (Read more September 11 stories.)

