Another nine were treated at the scene, but additional details about the victims and their injuries have not been released.
Jenny Koch, the zoo's marketing director, told The Denver Post that two vultures and a duck were killed by the hail. But the Colorado Springs Gazette quoted her as saying only one vulture and one duck were killed.
She did not immediately return a phone call yesterday night to clear up the discrepancy.
"It was hail the size I've never seen before," she told The Post.
"Basically chunks of ice ... It's frightening." Softball-sized hail was reported in the area, but it was smaller at the zoo.
About 3,400 people were at the zoo at the time, and dozens of vehicles in the parking lot were damaged.
The zoo will be closed today so employees can take care of injured animals and repair broken windows and skylights.
None of the children attending zoo camp were injured.
The Broadmoor Hotel and resort also was pounded by hail, and staff members are assessing the damage.
"It was a significant storm,"said Barry Brown, the hotel's vice president of sales and marketing.
Forecasters warned that runoff from the rain could cause flooding of small creeks, roads, underpasses and low-lying areas as more storms develop along the Front Range yesterday night.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)