ATLANTA (WAOK)-After the disappearance of a 2-year-old research monkey, Lawrenceville residents say they are concerned for their safety. Communities near the Yerkes National Primate Research Center are petitioning for the facility to be shut down. They have received an anonymous letter, claiming the center knew of the monkey’s disappearance for a full week before they informed the public. The facility says they did nothing wrong, claiming they believed the monkey was still on the 117-acre property. Now researchers with the center say they believe the monkey is dead, saying the animal either fell into a crevice or was taken by a hawk.