In the heat of the largest wildfire in California history, Verizon dramatically slowed down data speeds for Santa Clara County firefighters helping to battle the blaze and suggested the department should pay more for a better data plan.

Santa Clara County Fire Department Chief Tony Bowden wrote to the U.S. District Court of Appeals for the District of Columbia Circuit, saying the data slowdown — known as throttling — “had a significant impact on our ability to provide emergency services” for firefighters dispatched to the Mendocino Complex wildfires in Northern California. Bowden said Verizon knew the data slowdown affected the firefighters’ crisis response but did nothing. He provided email correspondence as evidence.

On Wednesday, Bowden’s comments became a flashpoint in the ongoing battle over so-called “net neutrality” rules, which long regulated how broadband providers can manipulate their networks but were recently repealed by the Trump administration. Bowden initially made the comments as part of a court battle over the issue.

In the emails, Verizon accounts manager Silas Buss initially suggested Bowden’s staff should upgrade to a $39.99 unlimited data plan in early July, before the Mendocino Complex fires, in order to restore data speeds that were being reduced under the terms of their existing plan. On July 30, when the fires were raging, Buss raised the suggested price to $99.99 per month to remove throttling.

Santa Clara County firefighters deployed to the two Mendocino Complex fires, which together have burned more than 400,000 acres so far, experienced internet speeds slashed to 1/200 that of previous speeds. Firefighters who battle wildfires rely on live document-based apps, such as Google Docs, to update information, and the speed reduction made the communication nearly impossible, said Bill Murphy, a public information officer with the Santa Clara County Fire Department.

Buss did not respond to requests for comment.