Chemical leak at a Woodland cannery turned fatal as more than 40 employees were hospitalized, at least two of them in serious condition, and nearly 1000 people were evacuated, authorities said.

Chlorine dioxide was leaked in the work area where tomatoes were processed, said Greg Robinson, battalion chief of the Woodland Fire Department. Ambulances and buses were used to transport the 43 employees of Pacific Coast Producers to the hospital, immediately after the chemical leak was detected.

The gas was leaked into the work area in the form of off-gassing, which occurs when an injection system carrying the gas became overloaded, The Sacramento Bee reported quoting Mona Shulman, company spokeswoman.

Chlorine dioxide is routinely injected during processing to keep the water and tomatoes sanitary as they go into canning, Shulman said. A number of the employees were sent to hospitals as a precautionary measure, she said.

Pacific Coast Producers is a grower-owned cannery and works round the clock during peak tomato-processing months. The processed tomatoes will not be affected by the incident, Shulman said.