Early reports from U.S. retailers, including Toys "R" Us and Macy's, suggest that this year's Black Friday has seen healthy crowds attending nationwide stores, but the buyers appear to be cautious about what -- and how much -- they are buying.

Black Friday, the name given to the shopping day following the U.S. Thanksgiving holiday, kicked off at midnight in many places across the country, with big retailers offering deep discounts at their stores and extended hours of service throughout the weekend.

At some retail stores, prices were slashed by as much as 50, 60, or even 70 per cent.

And in one case on Friday, the combination of large crowds of deal-hunters and killer discounts proved fatal.

A Wal-Mart worker in Nassau County, N.Y., died Friday morning, after he was trampled by shoppers storming into his store, shortly after it opened.

National Retail Federation spokesperson Ellen Davis told The Associated Press she was "not aware of any other circumstances where a retail employee has died working on the day after Thanksgiving."

ShopperTrak RCT Corp. reported that last year's Black Friday weekend accounted for about 10 per cent of the 2007 holiday sales totals.

The lineups for this year's Black Friday started early on Friday -- in some cases at the stroke of midnight.

Canadian shopping enthusiast Heather Gore described to CTV's Canada AM the long lineups at a Niagara Falls, N.Y., outlet mall where she was shopping at 12:01 a.m. on Friday morning.

"I have been coming here on Black Friday for the past five or six years," she said. "This year is the busiest I've ever seen it."

Gore, a Toronto lawyer and veteran cross-border shopper, said she had seen many Canadians at the malls on Friday morning.

Some U.S. retailers, in fact, appealed directly to Canadian shoppers, in an attempt to bring them across the border for Black Friday.

In Detroit, mall owner Taubman Centers Inc., offered a $20 gift card voucher to the first 2,008 vehicles travelling through the Detroit-Windsor tunnel between 5 a.m. and 10 a.m. on Friday.

"For those Canadians who make Black Friday an annual shopping tradition, we would like to be their shopping destination of choice," Taubman spokesperson Karen MacDonald said in a release.

Prior to Friday morning, however, many analysts were not predicting that the turnout at the malls on Black Friday and its accompanying weekend would necessarily save the holiday season for retailers.

Morningstar analyst Brady Lemos told The Associated Press that his organization was expecting the retail numbers "to be pretty bad across the board."

America's Research Group chairman Britt Beemer questioned how long the shoppers would remain in the stores as the weekend progressed.

"I think we are going to see the busiest Black Friday ever, but will it carry over past 10 a.m.?" Beemer told The Associated Press.

"The bottom line is a great Black Friday does not make a season."

With files from The Associated Press