SIOUX FALLS, S.D. — A tornado and powerful winds ripped through Sioux Falls late Tuesday night, Sept. 10, cutting open hospitals and businesses, flipping cars, downing trees and cutting power to 25,000.
The twister and winds estimated at over 100 mph tore through the several square miles on the south side of the city just before midnight, cutting through the city's populous south side, including West 41st Street, Sioux Falls' busiest commercial corridor.
No casualties or serious injuries were reported, but officials at a Wednesday, Sept. 11, briefing at 5 a.m. said a full accounting of the damage would have to wait until daybreak.
"We're anxious for the sun to come up here so that we get a better look at what we're facing," said Sioux Falls Mayor Paul TenHaken.
Sioux Falls police issued a no-travel advisory overnight due to downed power lines and trees, and the National Weather Service issued a flash flood warning for the city.
The darkened streets were alive with the flashing lights of emergency vehicles as they cut downed trees and checked damaged buildings and power lines. Many roads remained closed or blocked by fallen trees as the city started its morning commute Wednesday.
Xcel Energy spokesman Eric Pauli said about 8,500 customers in the city remain without power as of 5 a.m.
The smell of leaking natural gas permeated the air along one badly beaten stretch of West 41st Street just east of Kiwanis Avenue, just outside an Advance Auto Parts store missing large portions of its outside walls and roof. Felled trees crossed a nearby road. Across the street, a flipped car lay against another vehicle.
The tornado and winds collapsed or wrecked the integrity of 37 buildings, said Sioux Falls Fire Chief Brad Goodroad.
The tornado also damaged several medical facilities on the south side of the city including the Avera Heart Hospital of South Dakota and the adjacent Avera Behavioral Health Center, both on West 69th Street. Both facilities sustained visible structural damage. The tornado blew out the heart hospital's front doors, many windows and the emergency room bay doors, snapping large trees in half and throwing them into cars in the parking lot outside.
Some patients were transferred from the Behavioral Health Center to the heart hospital, while residents who lived nearby pitched in to help move patients, clear wrecked cars and road debris and direct health care providers rushing to the scene.
Some outdoor warning sirens failed to sound across the city as the storm struck, TenHaken said.
"There was actually a breach of our protocol in that not the entirety of the siren system was sounded," he said. "We're doing an internal investigation on why that happened, why our protocol was not followed."
Sioux Falls Public Schools, Sioux Falls Catholic Schools and Harrisburg School District were all starting classes two hours late, under the city's encouragement, TenHaken said. The Red Cross has set up a shelter. The city set up a central website for storm cleanup and response information, at siouxfalls.org/storm.
Todd Heitkamp, meteorologist-in-charge of the National Weather Service office in Sioux Falls, said the straight-line winds were responsible for the "majority of the damage" and he would have to survey damage Wednesday morning to verify what struck the city was indeed a tornado.
Reports of looting were inaccurate, TenHaken said. Employees of the heavily damaged auto parts store were checking out the structure and passersby mistakenly reported them for looting.
TenHaken and other officials were working from an emergency operations center in the Law Enforcement Center downtown. He posted an early morning video to his Twitter page asking people to avoid driving and calling 911 with non-emergency needs.
"Say a prayer for our city, if you would," he said.
TenHaken and other officials are expected to provide an update on the tornado damage to media at 10:30 a.m.