An exchange of gunfire. the easter weekend shootings coming on the heels of the random mass shooting in brooklyn tuesday that left ten people shot, and underscores nationwide concerns over gun violence. i say over and over again there are many rivers that feed the sea of violence. this is a national issue. its not a red state, a blue state. reporter: mass shootings, defined as when four or more people are shot in a single incident, are up 66% in just the last two years. already more than 130 mass shootings in the u.s. this year. now, mona, airbnb released a statement regarding the shooting in pittsburgh. what are they saying? reporter: they say they have a strict no party policy, and have banned that booking guest for life. and they re also considering legal options to hold them accountable. linsey? mona, thank you. this easter weekend may be one of the busiest travel weekends of the spring. the tsa is screening millions of people at airports across the