Firefighters suited up and trekked out to Wylie High School in response to a phone call about a letter containing a strange white substance Monday, March 5.

WHS secretary Mrs. Chris Blann opened the letter as she would open any ordinary letter and was startled to find white powder in the bottom of the envelope.

“I put it in [the] S.R.O.’s mailbox and emailed him that it was there,” Blann said.

Blann could not release more information due to the ongoing investigation.

“[Police and fire rescue] immediately came on scene and conducted an examination of the powder and they determined it to be corn starch,” Ian Halperin, Wylie ISD Executive Director of Communications/Community Relations, said.

News 8 discovered similar letters were being opened across the country the very same day. It was also confirmed that the FBI and U.S. Postal inspectors have launched a full investigation.

Investigators believe these letters may be linked to similar letters that were sent to schools across the nation in the past. As of March 20, the culprit’s whereabouts are unknown, leaving the culprit responsible at large for two years.