ST. LOUIS – St. Louis police are investigating a series of online death threats against the head of the City Emergency Management Agency in the wake of the May 16 tornado.

According to our news partners at the St. Louis Post-Dispatch, Police Chief Robert Tracy confirmed the threats during a Wednesday press conference.

Mayor Cara Spencer placed Sarah Russell, the head of CEMA, on paid leave pending an internal investigation. The mayor said Russell and other CEMA staffers were not at their office to press the button to activate the tornado sirens.

“Let me be clear: CEMA exists to alert the community when severe weather is coming. This office failed to do that in the most horrific and deadly storm that our city has experienced in my lifetime,” Spencer said. “We knew there was weather coming. We should’ve been at the button.”

FOX 2 News has learned the St. Louis Fire Department’s tornado siren button also did not work, meaning even if someone had pushed the button on Friday, the sirens still may not have gone off. Spencer said checking that equipment was also CEMA’s responsibility.