NEW YORK -- The FBI and New York City police are investigating an explosion that blew out part of the wind-shear detection system serving La Guardia Airport on Friday afternoon. The blast caused no air-traffic control problems, but raised concerns about who might have set off the device and why.
A one-page handwritten note found at the site linked the incident to the federal raid on the Branch Davidian compound near Waco, Texas, in February 1993. "This is in response to the Waco incident, for all our fallen brothers," the note read. It also carried a scrawled swastika.
The FBI said it was unclear whether the attack was vandalism, the work of copycats after the attack on an Amtrak train in Arizona last week, or an act of terrorism by an organized group.
"We are going to take it seriously until we know that we should not take it seriously," said Joseph Valiquette, a spokesman for the FBI in New York City.
The police were classifying the explosion as a crime of criminal mischief, but Deputy Inspector Robert Martin, head of the city police special investigations division, said, "We're giving it some significance because of the timing with the anniversary of the U.N. and, of course, other terrorist acts. We are thinking that this is serious."
Authorities would not say what type of explosive was used.
The blast occurred at 4 p.m. Friday at the old Flushing Airport, across Flushing Bay from La Guardia, police said. A police spokeswoman, Officer Kathleen Kelly, said someone had cut through the fence surrounding the old airport and attached "an improvised explosive device" next to what is called a low-level wind-shear alert system remote center.