![A poison hazard danger sign is seen in the town of Khan Sheikhoun, Idlib province, Syria on April 5, 2017.](/sites/default/files/multimedia_images_2017/cover_image.jpg)
A poison hazard danger sign is seen in the town of Khan Sheikhoun, Idlib province, Syria on April 5, 2017.
© 2017 Abdussamed Dagul/Anadolu Agency/Getty Images
A poison hazard danger sign is seen in the town of Khan Sheikhoun, Idlib province, Syria on April 5, 2017.