Many storefronts were shuttered, for example, in a neighborhood of Chinese-owned shops near Rome's central train station. And an agriculture farm lobby group said a survey of farm-hotels outside the capital indicated some superstitious Romans had headed to the countryside for the day.
The fears are all thanks to a purported prediction of a major Roman quake Wednesday attributed to self-taught seismologist Raffaele Bendandi, who died in 1979.
However, Paola Lagorio, president of the association in charge of Bendandi's documentation, says there's no evidence Bendandi ever made such a precise prediction.
Adam Burgess, a senior lecturer in sociology at the University of Kent said rumors like these tend to occur in "information vacuums," such as during war when there are situations of uncertainty.
In this case, he suggested, the viral rumor-mongering about a Roman quake may reflect a lack of trust Italians feel toward their government.
"In the Italian context this might be exacerbated by the more typical experience of the Italian state where even laws and legislation that are passed will often mean very little in practice," he said.
In such cases, even efforts by the government to put out correct, timely information can backfire.
Italian officials have taken extraordinary measures to try to calm nerves and debunk the myth.
The country's Civil Protection department posted a dense information packet on its website stressing that quakes can't be predicted and that Rome isn't particularly at risk. Toll-free numbers were set aside at city hall to field questions.
And the national geophysics institute opened its doors to the public to inform the curious and the concerned about seismology.
Alberto Michelini, a researcher at the institute, couldn't even get into the seismology room to check how many quakes had been registered Wednesday because it was so full of student groups and others visiting for the day.
Instead, he pulled the information up on his iPhone: 22 quakes before noon, the strongest a sequence of three quakes early Wednesday around Mt. Etna in Sicily registering magnitudes of 2.6, 2.9 and 3.1.
"We tried to take advantage of this moment of fear and psychosis to try to explain what we do," Michelini said.
That includes stressing that no one can scientifically predict an earthquake, but that preventative measures can be taken, such as constructing buildings in quake-prone areas according to anti-seismic norms.
"Maybe we should thank Bendandi and all this psychosis because we can take advantage of it to talk about earthquakes," he said. "Normally it's too difficult to speak about them because you only hear about them after they happen."