House lawmakers have announced plans to hold a hearing on the growing shortage of baby formula in the United States. Analysts say over 40% of baby formula products are now out of stock, with some brands near impossible to buy. The shortage is due in part due to the closing of a manufacturing plant in Michigan owned by Abbott Nutrition, the nation’s largest baby formula manufacturer. The plant was shut down in February over concerns about bacterial contamination following the deaths of two babies. A former worker at the plant had warned the Food and Drug Administration about problems at the plant in October, months before the babies died, but the FDA did not interview the whistleblower until December and didn’t inspect the plant until the end of January. The whistleblower had been fired by Abbott after raising concerns internally about safety issues at the plant.