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"We didn't get a proper warning," resident Nora Flores-Guerrero told KSAT. "They didn't post anything or send out any type of message to warn the residents."

"It looked like black sludge. They were comparing it to oil. (It was) that dark," she said, adding that it had a bad odor

City Waterand Wastewater Superintendent Carlos Ramirez said the water tower for the city has not been cleaned in 20 or 30 years.

In a statement issued Thursday, the city said draining its elevated tank caused sediments and deposits at the bottom to pass through residents' homes.

The city asked residents to boil or run water before using it.

A spokeswoman from the city's water department did not want to give her name, but told The Huffington Post that, as a precautionary measure, the city is giving bottled water to the elderly Friday.

The city is also giving portable water to homes affected by the issue.

This is only the latest problem among city officials in Crystal City.

A U.S. Department of Justice release issued Feb. 4 said that most elected officials have been arrested in connection to an illegal gambling ring.

According to the release, City Manager and City Attorney William James Jonas, III, 54; Mayor Ricardo Lopez, 40; Mayor Pro-Tem Rogelio Mata, 43; City councilman Roel Mata, 44; former City Councilman Gilbert Urrabazo, 45; and Texas businessman Ngoc Tri Nguyen, 38, were indicted on bribery charges.

City council member Marco Rodriguez was arrested in January on human smuggling charges. He admitted to being hired to transport undocumented immigrants.

The only council mayor not facing charges is Joel Barajas, who ran for office after being suspicious of government corruption.