MEMPHIS, Tenn. — Memphis-Shelby County Schools were locked down for hours Wednesday because of a threat made against Southwind High School that spread to other schools, Superintendent Marie Feagins said. Sheriff’s office: No longer a threat at schools; MSCS: Students can dismiss after lockdowns Feagins said the first threat came in by phone call to Southwind High School at 7:19 a.m. A threat appeared on social media shortly afterward, and there was a second call made to Southwind. MSCS was then alerted to social media posts making threats at other schools. At that point all schools were placed on lockdown, Feagins said. By 2:15, the sheriff's office announced on social media that there was no longer an immediate threat. School dismissal began soon after, though after-school activities were cancelled. "We have no reason to believe that there is a direct threat to any other school at this time," Feagins said. Three students at Whitehaven High were detained Wednesday in connection to a threat made to Whitehaven High School, Police Chief C.J. Davis said. However, the person who made the threat to Southwind has not been identified. Feagins said the school threats are not limited to Memphis, but are part of a national trend. "This is not a game. This is not play," Feagins said, addressing the person who posted the initial threat.