Three people are in critical condition after an explosion in East Flatbush Thursday night. Meanwhile, NYPD transit chief Mike Kemper is stepping down next month according to an internal document obtained by WNYC. Reporter Bahar Ostadan has the details. And finally, WNYC’s David Furst talks with a Rutgers marine and coastal science professor about why the ocean off the Jersey Shore has been frigid cold at times, despite the blistering heat.