More than 3,000 harried straphangers were evacuated Wednesday night after a frightening manhole explosion at a busy Brooklyn subway station. The FDNY responded to a 911 call about a transformer fire around 5:29 p.m. on Atlantic Ave. and Smith St. The explosion caused a Con Edison feeder that supplies the sub-station to go down; the feeder was supposed to have a redundancy that kicked in but never did, Con Edison, FDNY and sources told the Daily News. According to the MTA and sources, two trains were evacuated and a crowd-control plan was implemented; three other trains had to move back into a station with power. One person was injured and taken for treatment at NYU Langone in nearby Cobble Hill; three other straphangers refused medical help at the station. There were 3,500 passengers on two F trains that were stuck because of the explosive power loss, sources said. The explosion caused delays on the A, C, F and G train lines along Jay St. and Borough Hall at the Jay St. MetroTech station. The incident was declared under control at 8:20 p.m. Con Edison said it was continuing to investigate the manhole explosion and its aftermath. “We thank the hundreds of transit workers, firefighters, NYPD officers and responders from other agencies who worked to quickly assist riders on two trains stuck between stations following a Con Ed power failure,” MTA Transit President Demetrius Crichlow said in a statement. “Fortunately, evacuations were orderly and there appear to be no serious injuries. NYC Transit will work with Con Ed to understand how a limited outage in a redundant system could create a significant disruption to service.” MTA said via X that its officials tare investigating a loss of a third rail power. “A/C/F/G trains are severely disrupted between Brooklyn and Manhattan. No A/C trains between Broadway Junction and W 4 St-Wash Sq. What’s Happening? We’re investigating a loss of third-rail power near Jay St-MetroTech,” it said.