Of the 21 still in the hospital, eight remain in critical condition, Dr. Velmahos said.

WSJ: Doctors Treating Boston Marathon Victims Describe Injuries

Of the 21 still in the hospital, eight remain in critical condition, said Dr. George Velmahos.

WSJ: FBI Probe Heats Up in Deadly Boston Marathon Bombings

Two people, including one of the train drivers and a passenger, remain in critical condition.

BBC: Austrian trains in head-on crash

Three victims remain in critical condition at a local hospital, including Lt.

WSJ: Sikh Temple Shooter Died of Self-Inflicted Gunshot

Two survivors remain in critical condition in a nearby hospital.

FORBES: Night Search Begins For Bodies Of Russian KHL Hockey Players Downed In Crash

Education officials say two of the boys remain in a critical condition, as does one of girls from Protea Glen Secondary School.

BBC: South Africa pupils in hospital after lightning strikes