Dozens of children were hospitalized after a chemical leak at a YMCA pool in Durham, N.C. Wednesday afternoon.
It happened before 2:45 p.m. when about 100 campers were swimming in the pool.
Officials say a lifeguard noticed a strong chemical odor. The YMCA contacted EMS, which declared a hazmat situation.
Authorities said a mechanical issue caused sodium hypochlorite to mix with another chemical.
Police said the kids and adults who were exposed were showing symptoms such as vomiting, respiratory illness, and skin and eye irritation.
Forty children and two adults were taken to the hospital. Six children were in serious condition but have since improved.
By Wednesday night, most of the children had been released.