evidence: Here’s an interesting article about Thoreau’s early career and the incident that may have been a catalyst for his move out of town into the woods nearby. As it happened a year before the Walden experiment, it may have had some bearing on the idea. [...] On April 30, 1844, Thoreau started a blaze in the Concord Woods, scorching a 300-acre swath of earth between Fair Haven Bay and Concord. The fire was an accident, but the destruction of valuable woodland, the loss of firewood and lumber, and the narrowly avoided catastrophe that almost befell Concord itself angered the local residents and nearly ruined Thoreau’s reputation. For years afterward, Thoreau could hardly walk the streets of his hometown without hearing the epithet "woods burner." [...] Years before the fire, Thoreau wrote in his journal, "To regret deeply is to live afresh." And later in "Walden" he wrote that he came to the woods because he did not want to die having never lived. Perhaps this keen sense of urgency – the impulse to live the life he has imagined before it is too late – derives in part from Thoreau’s having witnessed how quickly an unthinking act can turn tragic.