SOUTH PHILADELPHIA — Flooding in the basement of Jefferson Methodist Hospital in South Philadelphia knocked out power Tuesday evening and forced the evacuation of more than 100 patients to other facilities. The power outage began around 6 p.m. after about three feet of water pooled in the basement and backup generators failed.

A total of 120 people were evacuated from the hospital, a spokesperson said. Northbound lanes of Broad Street from Ritner Street to Wolf Street were closed overnight as ambulances transported patients to other facilities.

With HVAC units shut off because of the outage, the interior of the hospital felt like it was over 100 degrees, according to Jefferson Health CEO Joe Cacchione. As of about 9 a.m. Wednesday, the facility was running on a combination of commercial and backup power, he said.

The emergency department opened to walk-in patients Wednesday morning before closing again. Officials said the hospital would likely remain closed for days or weeks while crews addressed the situation.

Officials said they were unsure of the origin of the water, though hospital officials said in a statement that the flooding was believed to have been caused by water entering the basement from an external source. PECO officials said the company's equipment was not responsible for the outage and that the facility's electrical systems were working safely.

Kathleen Elmasry, who had a family member at the hospital, described the scene as patients were moved. "It's scary for them. You know, for them it's scary," Elmasry said. "For me, I was worried because I didn't know what the result was going to be for everything. I just thought it was utter chaos."

"We are trying to do it as quick as possible," Cacchione said. "We are doing what we can to support them."

In a statement, the hospital said: "Due to power issues, Jefferson Methodist Hospital is temporarily closed. We are transporting patients to nearby facilities. Individuals seeking to reunite with family members or loved ones should call our information line at (215) 463-2031."