A slew of department store chains reported dismal first-quarter earnings on Tuesday, and the excuses for the bad reports were plentiful: a cooler start to the spring season, not having the right merchandise in stock and not having good enough promotions to draw shoppers in.

But the underlying issue remains: Department store operators haven't figured out how to bring customers into stores, when more and more customers are opting to buy things online from places such as Amazon, Rent the Runway and Stitch Fix or are heading directly to brands such as Nike and Kate Spade, skipping a trip to the mall.

Nordstrom reported fiscal first-quarter earnings after market close Tuesday that missed analysts' expectations, following similarly downbeat reports from Kohl's and J.C. Penney earlier in the day.

The news sent Nordstrom shares tanking more than 11% in after-hours trading. That's after shares of Kohl's hit a new 52-week low and closed the day down more than 12%, and Penney's stock dropped more than 7%. Shares of Macy's were down more than 1% in after-hours trading, having closed the day up nearly 1%.

Nordstrom reported earnings of 23 cents a share, adjusted, on revenues of $3.44 billion. Analysts were expecting adjusted earnings of 43 cents per share on sales of $3.57 billion, based on Refinitiv data.

Nordstrom also slashed its profit expectations for the full year, as the company said it had "executional misses" with its shoppers to start 2019. The retailer said it now expects to earn between $3.25 and $3.73 per share, down from a prior range of $3.65 to $3.90 a share. It's calling for net sales to be flat to down 2%, compared with a prior projection for growth between 1% to 2%.

Meanwhile, Penney's net loss nearly doubled during its fiscal first quarter, while Kohl's missed same-store sales expectations for the first time in two years.

America's department stores are still struggling, even as these retailers are working toward trimming their massive real-estate footprints, refreshing bricks-and-mortar stores with modern fixtures and adding more delivery options — all in hopes of wowing customers and winning sales.

Off-price chains such as TJ Maxx and Ross Stores have been stealing market share from department stores, as have Walmart and Target. These retailers are viewed as being more successful because their stores aren't found in shopping malls and they promise good value for customers shopping on a budget.

As of Tuesday's market close, Kohl's shares are down about 15.5% from a year ago, Penney shares are down 57%, Macy's shares are down 37%, and Nordstrom shares are down 17.5% over the past 12 months. The S&P 500 Retail ETF (XRT) has fallen just about 8% over the same period of time.