"They could be dangerous. They could be desperate," he told reporters.
The teens left their dorms around 11 p.m. Monday and began running around a large yard at the facility, Johnson said. The yard is surrounded by a fence, and at some point, they discovered a way out under the fence and escaped, he said.
It's not known if the escape was planned or was a spontaneous action, Johnson said.
source: cnn.com By Mariano Castillo and John Branch