For nearly two months, the world's window into the disaster has been through a battery of BP cameras, known as the "spillcam." The constant stream of spewing oil became a fixture on cable TV news and web feeds.
That made it all the more dramatic on Thursday when, suddenly, it was no more.
On the video feed, the violently churning cloud of oil and gas coming out of a narrow tube thinned, and tapered off. Suddenly, there were a few puffs of oil, surrounded by cloudy dispersant that BP was pumping on top. Then there was nothing.
"Finally!" said Renee Brown, a school guidance counselor visiting Pensacola Beach, Fla., from London, Ky. "Honestly, I'm surprised that they haven't been able to do something sooner, though."
Alabama Gov. Bob Riley's face lit up when he heard the news. "I think a lot of prayers were answered today," he said.
The next 48 hours are critical. Engineers and scientists will be monitoring the cap around the clock, looking for pressure changes. High pressure is good, because it shows there's only a single leak. Low pressure, below 6,000 pounds per square inch or so, could mean more leaks farther down in the well.
Thad Allen, the retired Coast Guard admiral overseeing the spill for the government, said they are deciding as they go along whether to release oil into the water again. At the end of the 48-hour test it's possible oil will start to flow again but, theoretically, in a controlled manner.
When the test is complete, more seafloor mapping will be done to detect any damage or deep-water leaks.
The saga has devastated BP, costing it billions in everything from cleanup to repair efforts to plunging stock prices. Though BP shares have edged upward, they shot higher in the last hour of trading on Wall Street after the company announced the oil had stopped. Shares rose $2.74, or 7.6 percent, to close at $38.92, still well below the $60.48 they fetched before the rig explosion.
The Gulf Coast has been shaken economically, environmentally and psychologically by the hardships of the past three months. That feeling of being swatted around — by BP, by the government, by fate even, was evident in the wide spectrum of reactions to news of the capping.
"Hallelujah! That's wonderful news," Belinda Griffin, who owns a charter fishing lodge in Lafitte, La., said upon hearing the gusher had stopped. "Now if we can just figure out what to do with all the oil that's in the Gulf, we'll be in good shape."
The fishing industry in particular has been buffeted by fallout from the spill. Surveys of oyster grounds in Louisiana showed extensive deaths of the shellfish. Large sections of the Gulf Coast, which accounts for 60 to 70 percent of the oysters eaten in the United States, have been closed to harvesting, which helps explain why one oysterman in Louisiana refused to accept that progress was afoot.