The Reputation's Numbers Plummeted?

Over the years and with subsequent revisions, the Langfords [Dan and Sandra] received daily e-mails from cycle tourists across Europe, North America, New Zealand, and Australia. Then the inferno struck. Book sales plummeted from 5,000 to 500 per year, and so did the trail’s reputation.
-- Myra Canyon's cyclists ready to roll again in The Georgia Straight, Thursday May 29 2008

Please enlighten me: How does a trail's reputation plummet from 5,000 to 500?