A massive explosion in Beirut killed at least 135 people and wounded 5,000 on Tuesday. Homeland security expert Juliette Kayyem told Boston Public Radio on Wednesday that "we know that it was not an attack, but it was the most remarkable form of negligence ever imaginable from a city to allow 2,750 metric tons of ammonium nitrate to be stored unsecure for over six years."

Kayyem is an analyst for CNN, former assistant secretary at the Department of Homeland Security and faculty chair of the homeland security program at Harvard University’s Kennedy School of Government.