Officials are investigating whether bird droppings may have caused December's shutdown of the Indian Point nuclear power plant.

A spokesman for Entergy, the operator of Indian Point, says it isn't uncommon for bird droppings to cause electrical outages. The process is called "streaming." It happens when a stream of excrement from a bird connects two lines, acting as a conductor and causing a shutdown.

The plant hasn't confirmed that bird droppings are the culprit behind the three-day shutdown of the reactor, but according to a report from the Nuclear Regulatory Commission, it is highly likely that was the cause. 

In a statement, the environmental group RiverKeeper said the outage "only demonstrates just how fragile the situation at Indian Point actually is."

While some residents were initially skeptical, one man summed it up: "Well, they stop airplanes, right?" he said referring to birds.

The plant is still conducting its investigation. If bird poop is ruled to be the cause, the plant will explore installing devices on the wires to make sure it doesn't happen again.