Fire personnel are also being trained to carry weapons for situations where their lives are in jeopardy.
From a sunrise event to a reading of victims' names at the time the bullets flew, Las Vegas on Tuesday was marking two years since the deadliest mass shooting in modern U.S. history, with memorials to the 58 people killed at a country music festival.
Interior Minister Hsu Kuo-yung told reporters about five people were feared to have been on the bridge when it collapsed.
Within minutes in Dayton, the first victims arrived at the Miami Valley Hospital emergency room in police patrol cars.
The bus had seat belts, but it's unknown if any passengers were wearing them.
Americans commemorated 9/11 with solemn ceremonies and vows Wednesday to "never forget" 18 years after the deadliest terror attack on American soil.
"These guys were in the worst possible conditions you could imagine a human being to be in,"