Bizarre explosion in New York's Central Park

The bizarre accident forced the amputation of 18-year-old Connor Golden's left leg below the knee and set the nation's largest city on edge a day before the July 4th holiday was expected draw thousands to watch the city's annual fireworks display.

New York City police officials said at an evening news conference that they had no evidence to indicate the blast was related to terrorism and had documented no credible threats against the city. But many questions about the case remain unanswered.

Deputy Police Chief John O'Connell said the explosion occurred near East 60th Street and 5th Avenue shortly after 10:50 a.m. Golden and two friends jumped off a rock and Golden landed directly on the explosive material. A New York City Fire Department spokesman said the blast nearly blew off Golden's foot, but his two friends were uninjured.

The explosion panicked parkgoers and could be heard nearby at the Orthodox Fifth Avenue Synagogue, where the funeral for Nobel laureate and Holocaust survivor Elie Wiesel was underway. Police said they do not think the blast was targeting the funeral.

O'Connell said the material was not an explosive device or related to commercial fireworks, but he did not give its chemical name or describe exactly how it was packaged.

Authorities said the material was "shock-sensitive," but not meant to go off by stepping on it. The material may have been placed next to the rock to hide it and could have been there for longer than a day. Police were using sniffer dogs to search the rest of the park for additional explosives but said none had been found by early Sunday evening.

"We believe this could have been put here as a part of an experiment," O'Connell said. He said he did not think that Golden or his two friends were involved in the creation of the explosive device or placing it in the park.

Golden was rushed to the hospital, where he was in surgery Sunday evening and was listed in serious but stable condition.

Golden's grandmother, Roberta Golden of Silver Spring, Maryland, said in an interview that her grandson had gone to New York with friends or had traveled to visit friends there. She said Connor's parents immediately left Fairfax to be with him.

"I can't believe it," Golden said. "My husband told me to sit down because he had to tell me something about Connor. I was afraid he was going to say Connor was dead."

Golden said her grandson just completed his freshman year at the University of Miami, where he is majoring in music engineering. She said he had graduated with honors from Oakton High School in Fairfax County and was an avid rock climber who especially loved climbing in Great Falls, Virginia.