Former Chargers coach Harland Svare lost a 1973 game against the Atlanta Falcons (41-0) and almost lost his life.

With the departure of the Chargers for Los Angeles looking likelier than ever, according to many accounts, do rowdy fans pose a real danger to what could be the team’s last days in Mission Valley? Presumably decorum will prevail, but beefed-up security planning also appears in order, say some city-hall insiders, fearing potentially violent confrontations with city officials.

In October, participants in an open forum at downtown’s Spreckels Theatre held by National Football League honchos faced mob-like heckling and intense booing, much of it aimed at Chargers special counsel Mark Fabiani. With mayor Kevin Faulconer still hoping to land a new taxpayer-backed stadium deal, increased police protection isn’t yet on the public agenda but can’t be ruled out. That could tack on additional taxpayer expense to the already costly Chargers relocation saga.

Besides this October’s meltdown, the historic model for bad fan behavior here dates back to October 21, 1973, when the Chargers fell to the Atlanta Falcons 41-0. “The mass above the tunnel entrance was seething — almost breaking the boundaries formed by a chain of police hand-in-hand,” wrote team psychiatrist Dr. Arnold Mandell about head coach Harland Svare’s walk of shame back to the locker room after the game. “Two of the cops had taken out their clubs and were swinging them threateningly in the air.”

Mandell was a UCSD professor and renowned expert on mind-altering substances who had been retained by Chargers then-owner Gene Klein to keep track of drug use by players. Mandell described the incident and another confrontation with the threatening crowd as he left the stadium in The Nightmare Season, his behind-the-scenes 1976 tell-all about the NFL’s underbelly.

“As I got to ground level, I faced a milling crowd of angry drunks, waiting for Harland,” Mandell recounted. Then it was the turn of Svare and wife Annette. “I had just reached my car when the mob stopped milling and turned as one toward the entrance to the underground lot. I heard Harland gun his motor a few times. I started back toward the crowd,” Mandell wrote. “Then I couldn’t see much because they were surrounded ten or twelve deep by screaming, gesticulating fans hurling insults, cans, bottles, rocks. The car couldn’t move forward. I got close enough to see some dauntless punks trying to soap the body and windows with obscenities. I had to fend constantly to keep from being knocked down and maybe trampled in the rush as the mob surged whenever Harland would gun the motor and inch the car forward.”

Added Mandell, “The hood and trunk were pocked with dents. A clumsy drunk leaped on the hood and jumped up and down grotesquely, giving them the finger before he slid off.” Finally, “sirens announced that a couple of police cars were on their way. Thank God.”

Concluded the psychiatrist after the confrontation had finally ended, “I just stood there for a while, trying to stop shaking, to get over the feeling that I had almost witnessed a lynching.”