Two people are now dead after an explosion brought down two apartment buildings in East Harlem this morning, and Mayor Bill de Blasio is confirming that a gas leak is to blame. At least 18 more are injured. A utility company says a resident in a nearby building reported smelling gas shortly before the explosion at 1644-1646 Park Ave. Con Ed dispatched two crews about 9:15am, but they got there too late. What's worse, the toll could rise: “This is an occupied building," a city official tells the New York Times. "There were people living there; we have people missing." (More New York City stories.)