While Seattle Public Utilities (SPU) continues to investigate the March 27 Tolt Dam false alarm, it has been confirmed that Federal Signal — one of SPU’s vendors — is to blame.

Federal Signal, “the leader in innovative equipment, signaling products and communication and security systems that keep workers, first responders and our communities safe and secure,” according to their website, was hired to build, install and commission the new alarm system in 2023.

“To date, we have learned that one of our vendors, Federal Signal, accidentally caused the activation while doing remote work on the system,” Seattle Public Utilities wrote in an April 2 update. “One of their employees failed to follow procedures by not turning off siren communications while performing the planned work.”

Federal Signal has since apologized to SPU and the Carnation community.

Carnation continues to seek legal counsel to discuss its next steps in holding King County and SPU accountable for the eighth false alarm since 2020.

“The city also reached out to the Federal Energy Regulatory Committee and is in the process of becoming an intervening party in an official capacity to oppose the dam’s re-licensing,” said Carnation Public Information Officer Ashlyn Farnworth. “The city understands the concern and trauma that residents have experienced over the last four years with the malfunctioning alarm systems. City officials are united in ensuring our concerns are heard.”

Following the false alarm on March 27, SPU has increased daily dam inspections and paused the weekly noon siren test on Wednesdays until further notice.

“SPU and Federal Signal are putting additional safeguards in place to ensure any work they perform does not impact the correct functioning of the system,” wrote Sabrina Register, a public information officer for the City of Seattle.

SPU is working with the King County Office of Emergency Management to ensure the community is notified in the event of a dam emergency through a Wireless Emergency Alert System similar to an Amber Alert.

The system will broadcast automatic Tolt Dam related messages to all cellphones in the affected area.

SPU is asking Carnation residents who heard the false alarm to email news.info@seattle.gov or complete a survey — which can be found on their website — to help with the information-gathering process.

SPU and the City of Carnation assure residents that the Tolt Dam remains safe.