Inspectors have braved danger on their way to the Zaporizhzhia nuclear plant in eastern Ukraine. They learned that shelling around the complex forced a reactor to shut down. The inspectors, from the International Atomic Energy Agency, say such threats underscore why they need to be there.

IAEA Director General Rafael Grossi led the team on Thursday through territory occupied by Russian forces. They are there to check on safety systems, assess damage, and evaluate working conditions. They met with Russian nuclear officials to discuss the risks.

Grossi said, "It is obvious that the plant and the physical integrity of the plant has been violated several times, by chance, by deliberation."

The inspectors faced challenges even before they arrived. They learned of an explosion near the plant, which the Ukrainian and Russian forces blamed on each other.

Grossi stayed at the complex for several hours before departing, but he left a contingent of inspectors behind to carry on with the mission. He says they will establish a continued presence and insists they are "not going anywhere."