The deadliest school fire in American history took place on - of all days - Ash Wednesday, March 8th, 1908, in the Cleveland suburb of Collinwood just after first period ended. Within a half hour, 172 students and three adults would be dead, or close to it.

Videos:

Cleveland Public Library: Collinwood school fire

Articles and books:

The Collinwood Tragedy: The Story of the Worst School Fire in American History, by James Jessen Badal The neighborhood never forgets Collinwood school fire: 100 years later, an angel still kneels over the children REMEMBERING THE LAKEVIEW SCHOOL FIRE (ALSO KNOWN AS COLLINWOOD SCHOOL FIRE)