<p>At least nine people were killed</a> in a deadly explosion on a train near Sennaya Square station in St. Petersburg, Russia, on April 3, forcing closure of the city’s metro and increasing security</a> at Pulkovo International Airport.</p><p>This footage was shot by a St. Petersburg Metro passenger who had just descended the escalator into the station as smoke from the explosion began spreading from the tunnel onto the passenger platform.</p><br />
