9/11/19 Argus Leader: ‘Human error’ led to most of Sioux Falls not hearing warning sirens ahead of Tuesday tornadoes


Joe Sneve, Argus Leader

Published 6:12 a.m. CT Sept. 11, 2019 | Updated 3:25 p.m. CT Sept. 11, 2019

The 911 dispatch center responsible for signaling the tornado warning sirens in Sioux Falls didn’t follow protocol, resulting in only a quarter of the city hearing outdoor warning sirens before three tornadoes touched down Tuesday night.

As winds reached more than 100 miles per hour and three EF-2 twisters touched down, Mayor Paul TenHaken said Wednesday during a morning news conference that a “breach of protocol” in the warning system was caused by human error by someone in the Metro Communications 911 dispatch center.

“Quite honestly what happened with the system is we just had a human error issue,” TenHaken said. “Only some of our sirens were activated.”

The 77-horn siren system in Sioux Falls is intended to be activated city-wide when a tornado is expected to touch down in Sioux Falls. But when Metro Communication got the alert from the National Weather Service that hazardous weather was imminent, an employee in the dispatch center only activated sirens in the southeast quadrant of the city, TenHaken said.

That left more than half the city without the added level of alert that sirens provide.

However, Todd Heitkamp, the meteorologist-in-charge at the Sioux Falls National Weather Service, said that people shouldn’t rely on outdoor warning sirens during inclement weather. Rather, they’re meant only to inform people who are currently outside that something life-threatening is happening, he said.

“I can tell you from my stance last night, I heard the siren only because I stood outside wondering what was going to happen right before the storm hit my house,” he said.

It’s one part of a larger system, Heitkamp said — if you’re indoors and trying to keep up with weather information, you should be using a weather radio, checking media reports or looking for warnings on a cell phone.

Sioux Falls isn’t the only city to have its outdoor warning siren system fail in recent months. According to media reports, similar failures occurred this year in other United States cities, including Belton, Mo.; Cleveland, Ohio; Daytona, Fla; and Oklahoma City, Okla.

Ben Smilowitz, executive director at the Disaster Accountability Project based in Washington, D.C., said its not uncommon for outdoor warning siren systems to fail. He blamed their unreliability on a lack of emergency management oversight from local jurisdictions.

“It’s often not taken seriously enough until something actually happens,” Smilowitz said. “Drills and preparedness events are usually intended to address these types of things, so having a drill every once in a while to see if some sirens work is pretty standard.”

T.J. Nelson, deputy chief staff of staff in the mayor’s office, said the Sioux Falls siren system is tested monthly during the spring, summer and fall months at 11 a.m. on the first Friday of the month.

City Hall could not immediately provide the report from the most recent test of the system that took place Sept. 6 or the locations of the sirens.

After realizing the siren system didn’t function properly and determining why, City Hall and other emergency agencies immediately began implementing changes to the software program that operates it. TenHaken said steps are being done to ensure 911 dispatchers will no longer have the option to activate only a portion of the sirens. Instead, when one siren goes off, they’ll all sound, he said.

Beyond that, Metro Communications will require a “buddy system” to activate the sirens, requiring two employees to cooperatively pull the levers that start the outdoor warning alerts.

“They’re a check and balance for each other when the call comes in to activate the sirens,” TenHaken said. “That’s something we’ll do right away.”

-Reporter Trevor Mitchell contributed to this story.