Hackers broke into the water treatment system of a city in Florida and attempted to increase the levels of an additive to a dangerous amount.

During a press conference yesterday, February 8, Pinellas County Sherrif said the perpetrators had remotely gained access to the system, which treats the water supply for around 15,0000 people who live in the city of Oldsmar.

They had attempted to increase the amount of sodium hydroxide in the water, also known as lye, by more than 100 times its normal level. While the additive is used in small amounts to control the acidity of water, higher levels of it are poisonous.

Luckily, the attempt was quickly thwarted and the city’s water supply was not affected, county sheriff Bob Gualtieri said.

‘The guy was sitting there monitoring the computer as he’s supposed to and all of a sudden he sees a window pop up that the computer has been accessed. The next thing you know someone is dragging the mouse and clicking around and opening programs and manipulating the system,’ Gualtieri said.

Authorities said that several other safeguards are also in place to prevent contaminated water from entering the water supply and that the remote access system, which was breached during the hack. has been disabled.

‘This is somebody who is trying, as it appears on the surface, to do something bad. It’s a bad act. It’s a bad actor. This isn’t just “Oh, we’re putting a little bit of chlorine or a little bit of fluoride, or a little bit of something,” we’re basically talking about lye that you are taking from 100 parts per million to 11,100,’ he added.

Once the hackers were kicked out of the system, the operator immediately reversed the change to the concentration,

‘At no time was there a significant adverse effect on the water being treated. Importantly, the public was never in danger,’ the sheriff added.

He said that even if the change hadn’t been caught, it would have taken more than a day to affect the water supply.

Florida Senator Marco Rubio said the hack should be treated as a ‘matter of national security’.

‘I will be asking the @FBI to provide all assistance necessary in investigating an attempt to poison the water supply of a #Florida city. This should be treated as a matter of national security,’ he said in a tweet.