CHICAGO - NFL Commissioner Paul Tagliabue convened an emergency summit Sunday morning with Vikings owner Zygi Wilf, pledging his assistance following one of the darkest weeks in franchise history. At Tagliabue's urging, Wilf created a new director of security position and immediately filled it by hiring Dag Sohlberg, a retired FBI agent who has worked five years as a part-time employee of NFL Security. The Vikings have wrapped security issues into their team operations department for years, but Wilf decided to split those duties following allegations last week that players participated in a sex party Oct. 6 on Lake Minnetonka.