According to the American Meteor Society there were two objects entered the Earth’s atmosphere. As it appears now, a small unknown object followed the fireball on its trajectory through the atmosphere.
Once the fireball gets very close to Earth, the unknown object can be seen colliding with the meteorite causing it to explode before it crashed down.
The American Meteor Society AMS has received nearly 700 reports so far about the fireball event over Northeastern US. The fireball was seen primarily from Maine but witnesses from Vermont, New Hampshire, New Jersey, Massachusetts, New York, Rhode Island, Pennsylvania, Connecticut, Ontario (Canada) and Québec (Canada) also reported the event.
The first video provides a detailed report of the event and in the second video you can see the huge fireball followed by a second object caught by a security camera of the Burlington International Airport as it plunges towards Earth before it explodes.