A huge sign greets you at the airport: “Welcome to Churchill, Manitoba: Polar Bear Country.” It lists the dos and don’ts: always be alert, and never walk after 10 p.m., for example.

Polar-bear warning signs dot the town’s edges and flash from most store windows. An eerie siren sounds every night as a reminder that it is time to get out of claw’s way.

Almost every discussion I had with residents included bears.

“Polar bears are why the town is here,” said Paul Ratson, a local nature guide.

While Churchill was once a Hudson Bay post, a port and a military town, it now largely relies on tourism to survive. And most of the tourists come during polar bear season: six weeks, starting in the middle of October, when polar bears are most likely to be seen around town, waiting for the sea ice to bump against the shore so they can rush off in search of seals.

The town’s population, normally 900, grows, with tour operators moving in to work seven days a week. Mr. Ratson said he makes 60 percent of his income during those six weeks.

So the big question on most minds was: Would the broken train line affect polar bear season? If Churchill was hobbling now, that would sound its death knell.

Most tour operators I spoke to remained confident it would not. Merv Gunter, the founder of Frontiers North Adventures, said tourists paid up to 11,000 Canadian dollars ($8,744) for a four-day polar bear package and booked a year and a half in advance. A bump in food prices would not deter those tourists.

The Tundra Inn owner Belinda Fitzpatrick agreed. While she had lost 30 percent of her summer bookings, she was not expecting any cancellations in October. “There are no independent tourists in bear season,” she said. “They all fly in.”