1 still in critical from Miami airport bus crash

"The alternatives are understanding and accepting that you can allow people's blood count to drop to levels that we used to think were dangerously low," he explained. "And we have learned how to manage people with lower blood levels. We have also learned how to reduce their demands for oxygen because the blood carries oxygen and we can actually take people and sedate them and depress their metabolism to slow them down so much that they demand less and less until they can reform their own blood."

Authorities said the bus driver got lost Saturday when the large bus hit the overpass, killing two passengers and sending 13 to the hospital.

"You can't bring in 13 people and not overwhelm an emergency room," Namias said. "But with the resources at Ryder, we've handled bigger and more. It was like a busy night."