PHILADELPHIA - According to the water department's advisory, approximately 18,000 customers are affected. This includes Wynnefield, Overbrook, and parts of Haddington, Carroll Park, and Haddington Park.

Residents of West Philadelphia were warned early Monday morning to boil their water to avoid contamination by disease-causing bacteria.

The system lost pressure due to a failed pump. The pressure was restored Sunday evening, but the water pipes still need to be flushed as the lack of pressurize could have caused the presence of bacteria.

Officials with the Water Department said that a pumping system failed on Saturday afternoon. This caused a pressure loss for properties within the zip code 19151 and in parts of 19131, and 19139.