A little more than a year ago, it was a mysterious sweet smell that mystified New Yorkers. This time a mysterious sinister smell. A psychological warfare experiment? From Reuters, Jan. 10:

A powerful, mysterious smell of gas wafted through much of Manhattan and parts of New Jersey on Monday, forcing building evacuations and a temporary suspension of commuter train service before dissipating by mid-afternoon.

Officials were quick to stress that the odor was not dangerous, but at least 19 people went to the hospital with minor ailments and its wide extent provoked jitters in a city that constantly reminded of the Sept. 11 attacks.

Twelve people were taken by ambulance to New York hospitals by emergency workers responding to calls from people complaining of upset stomachs, dizziness or difficulty breathing, a Fire Department spokesman said.

"It was all minor," said the spokesman, although he said a total of 409 fire trucks and hook and ladder rigs were scrambled to investigate the fumes -- about six times more than during a normal period.

A spokesman for ConEdison said the company had found no problems in its natural gas system that would have explained the smell.

"We did not find any gas leak or any problem on our gas system," spokesman Joseph Peta said. "At this point the cause of the odor remains a mystery."

Seven people went to the hospital seeking treatment in New Jersey, just across the Hudson River from New York, although New York City Mayor Michael Bloomberg said the odor was not dangerous and no unusual gas leaks had been found.

"It may just be an unpleasant smell, but at this point we do not know any more than that. The one thing we are confident about is, it is not dangerous," Bloomberg told a news conference.

"The city's air sensors do not report any elevated level of natural gas," he said.

The gas-like smell permeated lower Manhattan and was detected as far north as Central Park, across the width of the island, and in New Jersey.

A U.S. Department of Homeland Security spokesman said there was no indication of a terrorism connection.

Four schools in Manhattan were briefly evacuated, and the odor chased people out of landmarks such as the Rockefeller Center and Macy's department store.

"It was really, really bad then, so bad it gave me a headache," said Kate Browne, who lives in the West Village neighborhood and said she could smell the gas when she took her daughter to school.

"The emergency services turned up at my daughter's school looking for the leak then," she said.

Part of the New York-New Jersey PATH commuter train system, which carries 225,000 passengers a day, was closed temporarily as a precaution but normal service quickly resumed.

Several office buildings were evacuated and their air conditioning systems shut down, but city officials soon told building managers people could return to work.

"There have been no abnormal changes in gas flow in our gas transmission lines," a spokesman for power utility Con Edison said. He declined to answer questions.

Bloomberg said there had been a small gas leak in lower Manhattan, but that was not nearly enough to account for the wide range of the odor. The city was blanketed with low clouds and there was light rain and little wind.

The smell reminded some locals of an incident in October 2005 with the more pleasing scent of pancakes and maple syrup. That mystery also sent an unidentified scent through Manhattan and New Jersey and prompted a multi-agency investigation that proved fruitless.

Natural gas is odorless and a chemical called methyl mercaptan is added to it so that people can detect leaks. The chemical adds an odor similar to rotten eggs or sulfur, which was what people smelled during their morning commute.

Meanwhile in Texas... From AP, Jan. 9:

AUSTIN - Police shut down 10 blocks in downtown Austin for several hours Monday after 63 birds were found dead in the street, but officials said preliminary tests found no threat to people.

Workers in yellow hazardous-materials suits tested for contaminants in a cordoned-off section near the State Capitol and the governor's mansion before authorities finally gave the all-clear in the afternoon.

Although officials could not immediately determine whether poison or something else killed the birds, "there's no threat to humans at this point," Assistant City Manager Michael McDonald said.

The dead grackles, sparrows and pigeons will be tested for signs of poison or viral infections, according to Dr. Adolfo Valadez, medical director for the Austin and Travis County Health and Human Services Division. But officials do not believe bird flu is involved.

Determining the cause could take days or weeks, Valadez said.

Some experts said deliberate poisoning was the most likely cause of the die-off. "It happens quite frequently," said Greg Butcher, director of bird conservation at the National Audubon Society in Washington.

Grackles are a crowlike bird regarded as a major pest in Texas, with Austin sidewalks sometimes covered in their droppings.

The dead birds were found overnight along Congress Avenue, a major downtown thoroughfare. Police closed the route through downtown and two side streets, and a staging area was set up near the Capitol, with dozens of fire trucks, police cars and ambulances.

But the Capitol opened on schedule, and the governor was not asked to leave the mansion.

See our last post on fear in New York City.