To grateful parents and kids, the best, most compassionate teachers are heroes every day. But a few extraordinary ones become heroes in the literal sense. Whether saving a drowning student from an icy river or tackling a deranged gunman on the prowl, these eight teachers from around the globe exhibited "humble heroism" in the face of extraordinary danger:

1. Braving icy waters
Last week a 10-year-old autistic boy ran away from his teacher and onto an icy pond behind a Rochester, N.H., school. As the teacher and the principal, Gwen Rhodes, chased after him, the boy fell through the thin ice. Rhodes sprang into action, diving in and hauling the child to safety. It was a "shining example" of the kind of "heart" educators have, says Julie Ryan Evans at The Stir. Rhodes said it was all in a day's work: "What we do every day is what makes people who work in schools heroes."

2. Singing through a gunfight
In May 2011, automatic gunfire erupted outside a school in the northern Mexican town of Monterrey. A video that went viral shows a kindergarten teacher inside ordering her pupils to lie flat on the floor and assuring them that they are safe. The heroic teacher then leads the children singing "If All the Raindrops," a song made popular by Barney the Friendly Dinosaur, and their scared faces change to smiles. As the clip ends, the children lie on their backs, mouths open, pretending to catch chocolate raindrops. Outside, suspected drug cartel hitmen had executed five people.

3. Talking down a mad man
In December 2010, a teenager wielding two swords held a nursery school class hostage for more than four hours. While he let two teachers and fourteen students go free, six students and teacher Nathalie Roffet remained. Roffet talked to the hostage taker for hours, reasoning with him. While the teen talked to hostage negotiators on a cell phone, Roffet kept the kids distracted with lessons and puzzles until they were freed, and the teen arrested. The town's mayor said Roffet showed "remarkable sangfroid" in the face of such danger.

4. Keeping the class calm
On Nov. 29, 2010, a 15-year-old brandishing a gun walked into a classroom at Marinette High School in Wisconsin, and took 23 students and their social studies teacher, Valerie Burd, hostage for a "terrifying" five hours. Burd acted as a liaison with law enforcement, speaking with them by cell phone, and keeping the armed gunman calm until police burst through the door. While the student shot himself, the day could have been much more tragic had it not been for Burd keeping the situation under control. She was "nothing short of heroic," said the local police chief.

5. Sprinting to help
Two Utah friends were walking home from school in October 2010 when they were struck by lightening during a freak thunderstorm. Ron Hansen, a social science teacher at Snow Canyon High School, was the first to respond, sprinting out of his classroom after hearing a clap of thunder followed by screams. He found the two boys "lying on their backs smoldering." Hansen and another teacher brought the teens back to school where Hansen performed CPR until paramedics arrived, which is probably what saved their lives. "I don't think of myself as a hero," he said. "I was just there when it happened and was able to help."

6. An eye for injury
Billie-Jo Twigg figured the swelling in her leg was just the result of a pulled muscle, but her college professor knew better. Caroline Morgan, a U.K. biology teacher, took one look at Twigg's leg and recognized the symptoms immediately as deep vein thrombosis (DVT), a potentially fatal condition in which a blood clot forms in one or more of the body's deep veins. Twigg was sent to the doctor, where an ultrasound revealed three dangerous blood clots, which, if left untreated, could have traveled to her lungs and killed her. "Caroline telling me to go to a doctor literally saved my life," Twigg said.

7. Guiding to safety 
Robert Bailey is just one of the countless "unsung heroes" of the Japanese tsunami disaster that hit the coastal town of Ofunato last March. In his four years in the small town, the 27-year-old had gotten used to the daily rumbles of the Pacific's "ring of fire," but on that fateful Friday the ground shook with "biblical force." After the emergency system blared, Bailey and his 42 high school students had eight minutes before the massive tsunami would rip through their school. The teacher guided his class to the highest point he could find, where they watched and prayed as the rushing water threatened their perch. The group survived unharmed, but thousands more were not so lucky, which is why Bailey does not take credit for his actions. "He was just doing the job he was meant to do," his mother told Britain's Daily Mirror.

8. Tackling a gunman
It was the end of a school day at Deer Creek Middle School in Colorado and 57-year-old math teacher Dr. David Benke was helping at a crosswalk when he first heard a shot. He eyed the gunman's rifle and immediately calculated his next move. "I… realized that I had time to get him before he could chamber another round," Benke said. The teacher quickly tackled 32-year-old suspect Bruco Eastwood and held him down. While Benke said he worried he didn't do enough to prevent the shooting, which left two injured, he was lauded as a hero.

Sources: ABC News, AOL NewsFox News, Gimundo, Huffington Post, NY Daily News, The StirUSA Today