NEW YORK - New Yorkers living in the borough of Brooklyn woke to a strange sight on Tuesday -- a giant sinkhole had swallowed an enormous chunk of road.

The sinkhole, formed by the natural process of erosion, appeared shortly after 7 am at an intersection in the neighborhood of Sunset Park, according to the Fire Department. The gaping hole exposed torn pipes and crushed asphalt at the intersection of Fifth Avenue and 64th Street. No one was hurt.

Sinkholes can be gradual but are often sudden. A sinkhole in Guatemala in 2010, measuring 18 meters (60 feet) wide and about 30 meters deep, swallowed a three-story building and a nearby house when it suddenly formed.

At around 7 a.m. on Tuesday morning - way too early for something as literally earth-shattering as this to happen - the intersection at Fifth Avenue and 64th Street in the Sunset Park neighborhood of Brooklyn collapsed and sank into the ground to form a gargantuan hole, hence the term sinkhole. The sinkhole offers a rare glimpse of the mysterious world below New York City's streets, but alas, it's not all mole people, hidden treasure, and Ninja Turtles, as one might hope. Instead, it's mainly water and gas pipes, the exposure of which has prompted National Grid to arrive on the scene, presumably to make sure the sinkhole does not lead to a gas link and therefore, explosion.

Judging by footage of the sinkhole, it could have easily swallowed several cars, vans, trucks, and an entire family or jogging group. Luckily, it was early enough that that particular intersection was still empty when the sinkhole formed.

Moreover, New York's largest recorded outbreak of Legionnaires' disease has killed seven people and infected 86 others, as the city moved Tuesday to draw up new legislation to halt future outbreaks. Sixty-four people are still being treated for the illness, a form of pneumonia, in hospital since the outbreak began on July 10 in the Bronx, the poorest county in the state.

The disease is spread by a bacteria, which has recently been discovered in the cooling towers of five buildings in the area. Officials say those who died were older patients and had pre-existing medical conditions. Legionnaires' disease is not contagious and can be treated with antibiotics.

Those with chronic lung diseases, as well as AIDS and HIV patients are among those most at risk. "Our hearts go out to everyone who is inflicted and particularly the families of those we have lost," New York Mayor Bill de Blasio told a news conference on Tuesday. "In the context of New York City we have not had this problem in any appreciable level and now we're seeing a pattern it's obviously something we're going to act on very aggressively."

City hall has identified and de-contaminated five cooling towers, which were found to harbor the Legionella bacteria. New York's drinking water supply, fountains, shower heads and pools are safe and unaffected, authorities say. "It is not a contagious disease. It cannot be passed from person to person," said the mayor.

"There is no risk to our water supply from Legionnaires' disease. Another crucial point, it can be treated, it is treatable with antibiotics." Leaflets were distributed over the weekend to inform residents in the Bronx, where the outbreak has been concentrated, and invite them to a public meeting late Monday on the outbreak. The disease, a serious pulmonary infection, is spread by bacteria that thrive in warm water, such as that found in hot water pipes, air-conditioning systems and industrial ponds.

Infections result from inhaling airborne droplets of contaminated water. The incubation period lasts between two and 10 days. Anyone with symptoms such as fever, coughing and shortness of breath in the Bronx should seek medical attention immediately, officials said. De Blasio said July 30 was the peak of the outbreak and that there had been a reduction in recent days in the rate of new cases, and said the city was working to prevent future outbreaks.