49ers’ fall was stunning and swift

TEMPE, Ariz. — In terms of personality, there may not be an NFL coach better equipped to handle calamity than San Francisco’s easy-going Jim Tomsula. That’s important because the 49ers are a full-fledged natural disaster this season.

Massive roster turnover, a new coaching staff, poor quarterback play and poor management have turned a recent powerhouse into one of the league’s laughingstock franchises.

San Francisco is less than two years removed from its third straight NFC Championship game, but you’d never know it by the weekly results. The 49ers are in a three-way tie for last in the NFC standings at 3-7, their once vaunted defense is ranked 28^th in the NFL and has surrendered more points than all but five conference teams, and their 139 points scored are the fewest in the NFL, trailing the next closest team by 40 points.

“The one thing I believe is that certain storms, you can’t go around,” Tomsula told Arizona media on a conference call Wednesday. “You’ve got to go right through them, and we’re steering right through.”

The seeds for San Francisco’s rapid demise began last season (or even earlier) during a well-publicized feud between then-coach Jim Harbaugh and GM Trent Baalke that eventually pulled owner Jed York into the fray.

Harbaugh departed to coach the University of Michigan, forfeiting the final year of the five-year, $25 million contract he signed in January 2011. While the Wolverines are a freak loss to Michigan State away from a possible berth in the College Football Playoff — one year after a 5-7 season under Brady Hoke — the 49ers are in disarray and Harbaugh’s departure was the crack that burst open the dam.

Offensive coordinator Greg Roman left to take the same position with the Bills and other key staff members were cleared out. Seven-time Pro Bowl linebacker Patrick Willis announced his retirement in March, talented rookie linebacker Chris Borland retired days later, citing injury concerns, running back Frank Gore signed a three-year deal with Indianapolis, guard Mike Iupati signed a five-year deal with Arizona and a host of other players departed for various reasons.

Of the 53-man active roster from the 49ers’ 2012 Super Bowl season, just 16 players remained at the start of the 2015 season.

“It was difficult,” linebacker NaVorro Bowman said of the mass exodus. “Us having the success that we’ve had and then just having a new team — all those things were kind of challenging to deal with.

“I try to go out there and do what I can, but I can’t do everything. Leading by example is all I can do. That’s the best way for us to even understand the type of players we had in the past when we were successful.”

Quarterback Colin Kaepernick may not be around when the 49ers finally figure things out. He was benched in favor of Blaine Gabbert prior to the Niners’ Nov. 8 game against the Atlanta Falcons. He went on injured reserve Saturday after surgery to repair an extensively torn labrum in his non-throwing shoulder.

Kaepernick completed 144 of 244 passes this season (59 percent) for 1,615 yards, six touchdowns, five interceptions and a lowly passer rating of 78.5. His regression has led to rampant speculation that he won’t be back.

“It sucks what happened to Kaep,” Iupati said, when asked about facing his former team for the first time this Saturday at Levi’s Stadium in Santa Clara, California. “I do care about them. They’re having a tough season. I don’t know what’s going on over there but I believe they have a really good team.”

Iupati was quick to remind those reporters who were writing off the 49ers that Arizona hasn’t beaten the 49ers on the road since 2008 — a string of six straight losses — and San Francisco is 3-2 at home. The warning wasn’t convincing, however. Neither were the positive vibes Tomsula was trying to generate.

“They’re a resilient group,” Tomsula said. “Through the course of the year, we’ve had more (challenges) than most, but there’s a good group around me.

“The one thing I will say is that there are people here that I can lean on and we are working through it together.”

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A partial timeline of the 49ers’ rapid demise

Dec. 28 — Coach Jim Harbaugh departs to coach Michigan, ending his four-year tenure with a 44-19-1 record, two NFC West Division titles, three trips to the playoffs, three NFC Championship appearances and one Super Bowl appearance.

Jan. 12 — Offensive coordinator Greg Roman takes OC job with Buffalo.

Jan. 15 — Defensive coordinator Vic Fangio, secondary coach Ed Donatell and linebackers coach Jim Leavitt are released their contracts.

March 11 — Seven-time Pro Bowl LB linebacker Patrick Willis announces his retirement.

March 11 — RB Frank Gore signs 3-year deal with Colts after leading 49ers in rushing every season since 2005.

March 11 — G Mike Iupati signs five-year free-agent deal with Cardinals.

March 11 — LB Dan Skuta signs five-year contract with Jaguars.

March 13 — CB Chris Culliver signs four-year deal with Washington.

March 14 — CB Perrish Cox signs three-year deal with Tennessee.

March 16 — LB Chris Borland retires after one season, citing injury concerns.

March 24 — Troubled DT Ray McDonald signs 1-year deal with Bears.

April 13 — WR Michael Crabtree, the leading receiver in 2011 and 2012, signs 1-year deal with Oakland.

May 19 — Five-time Pro Bowl DL Justin Smith retires.

June 5 — RT Anthony Davis announces surprise retirement to heal.

Sept. 3 — 49ers release DL Darnell Dockett six months after signing him to two-year deal, learning what the Cardinals already knew: that he was done.

Sept. 10 — DE Aldon Smith signs with Oakland on the same day The Santa Clara County District Attorney’s office charged Smith with three misdemeanors: DUI with prior conviction and refusal to submit to chemical test, hit and run with property damage, and vandalism.

Nov. 3 — RB Reggie Bush placed on IR with a torn medial collateral ligament.

Nov. 21 — QB Colin Kaepernick placed on IR left shoulder injury.

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