The relentlessly breathless NFL news cycle began normal enough for Vikings fans at 6:25 Tuesday morning when someone tweeted a photo of Bengals defensive coordinator Mike Zimmer checking in with a Minneapolis gate agent inside the Cincinnati airport.

It was official. The front-runner among 10 candidates in General Manager Rick Spielman’s three-week search to replace fired head coach Leslie Frazier was on his way to the Twin Cities for a second interview that would include team owners Zygi and Mark Wilf.

By 10:30 a.m., reporters began to gather outside the team’s Winter Park facility. Helicopter TV coverage was put on hold, meaning the 57-year-old Zimmer’s impending arrival wouldn’t rise to the level of Brett Favre’s welcoming party in 2009. But there were cameras on hand to capture the man who soon could become only the ninth head coach in the Vikings’ 64-year history.

Shortly after 11 a.m., a local television station had posted video of a black Town Car with Zimmer inside pulling into Winter Park. Zimmer went inside the building and then, well … nothing. At least no decisions were made as of late Tuesday.

Hours passed with Zimmer and the Vikings still inside the building. No word from the team was passed to the outside world. No puffs of smoke. No response to multiple messages left for Spielman.

The day ended with Zimmer as neither the head coach nor out of the running. Contacted as he was entering the elevator in the lobby of his hotel shortly before 10 p.m., Zimmer said the Vikings had not offered him the job.

Meanwhile, as Zimmer and the Vikings holed up inside team headquarters, the endless NFL news cycle churned furiously outside.

In Tennessee, Ken Whisenhunt, the offensive mind that led the historically moribund Cardinals franchise to its only Super Bowl appearance during the 2008 season, was introduced as Titans head coach. Discussion quickly shifted to who his coordinators will be.

In Detroit, Jim Caldwell, the offensive mind who succeeded Tony Dungy in Indianapolis and led the Colts to the Super Bowl in his first year as a head coach in 2009, was named head coach of the Lions.

That left only the Vikings and Browns without head coaches. The Browns appeared content to wait for Broncos offensive coordinator Adam Gase, who refuses to interview anywhere until Denver’s season is over.

Meanwhile, Cardinals defensive coordinator Todd Bowles backed out of the Browns’ search Tuesday. He was believed to be in line for a second interview with the Vikings this week, but there has been no confirmation of one being scheduled. He likely would interview again only if the Vikings say no to Zimmer.

In Zimmer, the Vikings are bucking a recent trend of hiring offensive-minded coaches. Seven of the eight head coaches hired last year and four of the five hired so far this year are offensive-minded coaches.

Zimmer, who never has been a head coach, has been an NFL defensive assistant for 20 seasons, including the past 14 as a coordinator for three teams: Dallas, Atlanta and the past six seasons in Cincinnati.

Of course, there’s a reason a successful defensive mind has made it this far in the Vikings’ coaching search. The 2013 Vikings ranked last in points allowed (30.0 per game) and blew five leads in the final minute of regulation, turning what could have been a 10-6 season into 5-10-1.

In Dallas, where he spent four seasons working for Hall of Fame coach Bill Parcells, Zimmer led the Cowboys to top-10 finishes in yards allowed using both the 4-3 and 3-4 schemes. In 2003, they ranked No. 1.

In Cincinnati, Zimmer posted top-10 rankings in four of the past five years, including No. 3 this season. Before Zimmer arrived, the Bengals posted only one top-10 ranking in the previous 18 seasons.

The Bengals also ranked fifth in points allowed (19.1) this season. That included a 42-14 rout of the Vikings in Week 16.