ST. LOUIS—Mayor Cara Spencer said Wednesday that city officials believe that warning sirens were never triggered Friday during the tornado that struck the region, and that if it was, it would not have worked from the location where it would have been activated.

Late Tuesday night Spencer announced she's placing Emergency Management Commissioner Sarah Russell on paid administrative leave as part of an external investigation "into the actions of the City Emergency Management Agency on Friday, including the failure of the outdoor warning siren system." An acting commissioner has been named until the city finds a replacement.

Spencer had said "human failure" was responsible for the fact that sirens weren't activated Friday when a tornado struck the city, killing five people. Earlier Tuesday, Spencer signed an executive order that she said clarified protocols that had previously been unclear when it came to who was ultimately responsible for activating the sirens. That will now sit with the fire department.

In a news release late Tuesday night, the Spencer administration offered its fullest accounting to date of what it said unfolded Friday. The city confirmed that the emergency management staff, including Russell, were at a workshop at 1520 Market Street and not at the agency's office at 1915 Olive to physically activate the warning siren.

When the tornado warning was issued by the National Weather Service, Russell called the fire department. The city released a recording of the call Tuesday night, where Russell can't be heard identifying herself and did not have the correct time for the warning. Russell asks if "You got the sirens"? A fire dispatcher says yes. Russell says thank you so much and the call ends after just over a minute.

The mayor's office says the directive to activate the sirens was ambiguous. 

On Wednesday, Spencer said after listening to the call, she's unsure if the dispatcher knew it was Russell on the other end of the line and that the dispatcher hasn't answered that question definitively. Fire Chief Dennis Jenkerson said he's spoken to the dispatcher's supervisor, but that further information would come from the outside investigation.

"I remain shocked and frankly a bit horrified by the issues in the system…but I’m also very confident that we can activate the system when and if it’s necessary in the coming days weeks, months years ahead," Spencer said.

St. Louis Fire Captain John Walk will lead CEMA until a permanent replacement is named.

The city also said that according to the former activation policy, the warning sirens were to be activated at the Fire Alarm Office at the St. Louis Fire Department headquarters.

Test of the emergency system Tuesday revealed that the activation button at the fire department did not work. While repairs are made, the fire department will be staffed at CEMA headquarters to push the button in the meantime if necessary.

“We’re about redundancy and resiliency. We cannot have a failure in any point of any type of policy or any kind of mechanical device. We have to have backups,” Jenkerson said earlier Tuesday before the test, adding that “marginal” equipment is in the process of being replaced. He said Wednesday an unspecified number of sirens were damaged as a result of Friday's storm.

"There will be gaps", he said.

"When I say the system is good, it will be good and it will be redundant," Jenkerson added. "I’ve got complete trust in the fire department. You can see the job we’ve done over the last three-four days. If that wasn’t a show of the ability, experience, that’s what we do, I’ll make sure this works."