That's 11 years after this crash. And according to the July 2019 article that lead me to the crash story:
Acquired by Marriott Corporation in 1971, it grew to more than 130 locations nationwide.
It was sold to a San Francisco investment group in 1988, but most locations had closed by 1990. The last original location closed in 2006 in Eugene, Oregon.
In 2009, Lake Forest-based Parlour Enterprises Inc. revived the company, buying the rights to the brand in the mainland United States. In the next few years it opened seven shops, in Brea, Santa Clarita, Rancho Cucamonga, Riverside, Mission Viejo, Buena Park and Sacramento.
That seems to indicate they continued to expand for a decade after the crash, and started running out of gas in the mid 80s. They carried on like a Zombie into the 00's and were kaput (the first time) by 2006. I think we can conclude they died of stale management; like Ruby Tuesday's, not because of a terrible, freak accident almost 35 years earlier. In fact, they had enough brand equity to revive and survive for 10 years almost exclusively in California.