(For a Reuters live blog on US., UK and European stock markets, click LIVE/ or type LIVE/ in a news window.) * Retail sales rise unexpectedly in June * S&P 500 energy index tumbles * Moderna hits record high on S&P 500 addition * Indexes: Dow -0.42%, S&P 500 -0.33%, Nasdaq -0.29% (Updates with afternoon trade) July 16 (Reuters) - Wall Street fell on Friday, weighed down by declines in Amazon and other heavyweights technology stocks, while investors worried about a rise in coronavirus cases tied to the highly contagious Delta variant. On Thursday, Los Angeles County said it would reimpose its mask mandate this weekend. On Friday, public health officials said U.S. coronavirus cases were up 70% over the previous week, with deaths up 26%. Cruise lines Carnival Corp and Norwegian Cruise Line both tumbled over 4%. “COVID is starting to affect the market, ironically, for the first time since last summer, when the reopening trade began,” said Jake Dollarhide, chief executive officer of Longbow Asset Management in Tulsa, Oklahoma. Amazon and Nvidia were each down about 2%, weighing more than any other stocks on the S&P 500. The S&P 500 technology sector index dipped 0.4%, down for a second session after hitting a record on Wednesday. The utilities index climbed 1.1%, while the real estate index rose 0.6% to a record high. This week, investors have balanced worries about a recent inflation spike with reassurances from Fed Chair Jerome Powell that the surge in prices is temporary. Second-quarter earnings season picks up next week, with reports from companies including Netflix, Johnson & Johnson, Verizon Communications, AT&T and Intel. Analysts on average expect 66% growth in earnings per share for S&P 500 companies, according to IBES estimate data from Refinitiv. With the S&P 500 up about 16% so far this year, investors will look for strong company forecasts to justify sky-high valuations. “It’s been hard for the market to gain here from these already elevated prices,” said Rick Meckler, partner at Cherry Lane Investments in New Vernon, New Jersey. The S&P 500 energy sector index dropped 2.4% and was on track to lose about 7% for the week, with investors worried about expectations for more supply and a rise in coronavirus cases that raised demand concerns. Data from the Commerce Department showed retail sales rebounded 0.6% last month as spending is shifting back to services, bolstering expectations that economic growth accelerated in the second quarter. In afternoon trading, the Dow Jones Industrial Average was down 0.42% at 34,840.24 points, while the S&P 500 lost 0.33% to 4,345.67. The Nasdaq Composite dropped 0.29% to 14,501.66. Moderna Inc jumped 7% to a record high after S&P Dow Jones Indices said the drugmaker will join the S&P 500 index as of the start of trading on July 21, replacing Alexion Pharmaceuticals. Cintas Corp rose over 4% after brokerages raised price targets on the business service provider’s stock following its fourth-quarter results. Didi Global Inc fell nearly 4% after China sent state officials from at least seven departments to the ride-hailing giant for a cybersecurity review. Declining issues outnumbered advancing ones on the NYSE by a 1.76-to-1 ratio; on Nasdaq, a 1.54-to-1 ratio favored decliners. The S&P 500 posted 48 new 52-week highs and no new lows; the Nasdaq Composite recorded 41 new highs and 91 new lows.