UPDATED with trading resuming:  Investors looked on with concern today after the New York Stock Exchange stopped trading for all its stocks at 11:32 ET — resulting in one of the longest suspensions in memory.

The system came back online at about  3:10 ET, with less than an hour left in the trading day. That means the exchange was down for more than 3 1/2 hours.

“The issue we are experiencing is an internal technical issue and is not the result of a cyber breach,” the NYSE said earlier today. “We chose to suspend trading on NYSE to avoid problems arising from our technical issue. NYSE-listed securities continue to trade unaffected on other market centers.”

White House Press Secretary Josh Earnest also says that there’s “no indication that malicious actors were involved.” NYSE officials have been in touch with the Department of Homeland Security, and the Securities and Exchange Commission as well as the Treasury Department and are “working feverishly to try to resolve the situation.”

President Obama was briefed by United States Homeland Security Advisor  Lisa Monaco, and will receive updates throughout the day.

When trading stopped the Dow Jones Industrial Average was down about 215 points, or 1.15%, as investors grappled with a slump in China’s stock market. The NYSE said that it would cancel all open orders. Trading continued without change on its options exchange as well as Nasdaq.

Major media stocks that trade on the NYSE include CBS, Disney, Time Warner, Time Warner Cable, and Lionsgate. Nasdaq is the exchange for  Comcast, Viacom, Fox, Discovery, DreamWorks Animation, DirecTV, Dish Network, and Starz.

NBC News cut into programming with a Special Report on the NYSE situation anchored by Lester Holt, joined by CNBC’s Bill Griffin and NBC News’ Pete Williams. CBS News aired a four-minute report at 12:25 ET anchored by Jim Axelrod.

In addition the NYSE snafu, the Wall Street Journal‘s web site temporarily crashed, at least for visitors on the east coast. “Something did not respond fast enough, that’s all we know…” the site said. It now offers headline stories but also notes that it is “having technical difficulties. The full site will return shortly.”

Earlier today United Airlines grounded 4,900 worldwide flights citing “a network connectivity issue” — although CNBC reports that government officials don’t believe there’s a connection. The airline attributed its problems to a faulty router.

Contributing: Lisa DeMoraes