Online searches to cancel AT&T wireless services spiked 567% today during the telecom operator’s nationwide outage, according to Google search data.

Customer dissatisfaction, which already runs rampant at communication service providers (CSPs), is coming fast at AT&T in the form of more than 74,000 users reporting service outages between 3:30 a.m. and 6:50 a.m. ET today.

The outage affected areas like Houston, Chicago, Dallas, Los Angeles and Atlanta, but Arkansas residents reported having the most issues per capita. The state led online searches per capita for the terms “ATT down,” “ATT outage,” and “network outage.”

The telecom operator released a statement acknowledging the issue and shared its active intention to restore service.

“Some of our customers are experiencing wireless service interruptions this morning. We are working urgently to restore service to them. We encourage the use of Wi-Fi calling until service is restored,” the company said in a statement.

By late morning, AT&T shared that 75% of its network had been restored.

The AT&T outage also caused spikes in interruptions to rival CSP services, including those from Verizon, T-Mobile and UScellular, according to user reports. Wireless carrier Cricket – which is owned by AT&T and uses its networks – reported about 14,000 outages at the event’s peak. Verizon reported fewer than 5,000 outages.

However, T-Mobile told the Associated Press that it had no outages. The 2,000 outages Downdetector reported for T-mobile customers were likely the result of users attempting to connect with other downed networks, according to T-Mobile.

Feds investigating outage to determine cause

The Federal Communications Commission (FCC), which oversees radio, wire, satellite and cable communication, says it is actively investigating the AT&T outage. The U.S. Cybersecurity and Infrastructure Security Agency (CISA) is also working with AT&T to determine the cause of the outage, Reuters reported.

ABC News reports that the FBI and Department of Homeland Security (DHS) are now investigating to determine whether the outages are the result of a cyberattack or a technical malfunction.