Explosion came from a car 'trying to enter the US from Canada' All four land crossings between the two countries are now closed The FBI in Buffalo is investigating; it's unclear if there are any injuries An attempted terror attack on Rainbow Bridge at Niagara Falls today saw a car explode, causing a massive explosion at a toll checkpoint that killed the vehicle's two occupants. Fox News cites law enforcement sources who say the intention was a larger attack to kill more. It remains unclear if anyone aside from those in the car were injured. The City of Niagara Falls...