Smart Energy Plan

May 15, 2026

After Tornado, a Stronger Grid Rises in North St. Louis

Damaged line rebuilt with storm hardening upgrades supports 1,300 customers

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The tornado that swept across St. Louis on May 16, 2025, caused significant damage to electric infrastructure across the city. The storm broke more than 800 wooden utility poles, setting off a multi-day effort to safely restore tens of thousands of customers affected by this damage. The night of the storm, Ameren Missouri had more than 500 crews on the ground – a number that grew to more than 2,000 crews as contractors and utilities across the country sent reinforcements to St. Louis.

“We knew from the start this would be a large and challenging restoration effort,” said Landy Wince, senior director of operations. “Our crews, contractors and partner utilities worked to restore customers as quickly and safely as possible, and we also looked for opportunities to make parts of the system stronger as we rebuilt.”
 

A Corridor Hit Hard

Just before crossing the Mississippi River into Illinois the May 16 tornado tore across Hall Street, an important manufacturing corridor in north St. Louis. The impact caused wood pole after wood pole to snap, in what is known as cascading damage.

Replacing a single pole can take a three-person crew about four hours. Due to the extensive damage, it took crews multiple days to restore power to the Hall Street circuit, known as Maline-81. But they did more than just rebuild the line. By leveraging its Smart Energy Plan, Ameren Missouri was able to build storm-hardening benefits directly into this restoration work.
 

Customer Benefits Built into the Rebuild

This section of Maline-81 was slated to receive storm-hardening upgrades later in 2025 when it was hit by the May 16 tornado. Thanks to strategic planning, all the materials for that work were ready to deploy as part of Ameren’s restoration response. Ameren designers and engineers worked in the field with crews from Intren to complete a rebuild of the damaged section in just five days.

“This was an incredibly complex rebuild, involving more than 25 broken wood poles and two high-powered 34kV lines spanning about half a mile down the road,” said Doug O’Brien, electric distribution designer for Ameren Missouri. “To execute the upgrade as designed, crews not only rebuilt the damaged line but constructed an entirely new, storm-hardened line across the street to support customers served by the Maline-81 circuit.”

• Upgrades included stronger poles, as crews installed composite poles designed to better withstand severe weather and reduce the risk of cascading damage.
• They also included wire upgrades, with older conductor removed and replaced with stronger wire built to carry more capacity.
• In addition, storm response improvements were made by relocating Maline-81 to the other side of the street, creating more separation from another circuit in the area. That separation gives crews additional options to reroute and restore power more quickly after future disruptions and reduces the chances of losing both circuits at the same time.
• The project also adds smart technology in the form of smart switches that allow parts of the circuit to be restored automatically when outages occur. Smart switches have prevented more than 400,000 outages during storms since 2021.
• Together, the upgrades are expected to support service reliability for more than 1,300 customers and two substations in the area, including major manufacturers.

The quick action in response to the May 16 storm allowed Ameren Missouri to bring these benefits to customers months ahead of schedule. The remaining work on other portions of the circuit is expected to be completed in 2026. 

For more information on Smart Energy Plans in your area, visit Ameren.com/Reliability.