(CNN) -- There is not always time to wait for fire trucks or ambulances to arrive. Sometimes an emergency situation is so dire, the danger so imminent that there is need for people to take immediate action.
Sometimes it's a group of neighbors who are near a vehicle that has burst into flames. Other times it is an off-duty firefighter or police officer who just happens to be near the scene of a blaze or accident. In one case, it was a young man diving into the strong waters of a river to save someone from drowning.
What these people share in common is quick thinking and the disregard for their own safety in the attempt to help save a life.
CNN.com takes a look at some of the stories of heroic acts that happened throughout the country in the past 12 months.
Neighbors pull 4-year-old, family to safety
Firefighters were on the way, but neighbors realized time was running out quickly for three people trapped in a burning minivan.
The van had struck a tree, flipped over and caught fire on a July afternoon in Milwaukee, Wisconsin. A video shot of the accident by one of the neighbors rushing to the scene shows the chaotic scene and the flames enveloping the back of the vehicle.
"People were everywhere," Dawn Nyklewicz told WISN. "I mean, it's amazing. This whole neighborhood was just amazing to see 10, 15 people in there crashing the windows open, trying to get these kids and the mother out. It was just amazing to see it."
One neighbor got a fire extinguisher. Another got a hose.
She focused the water on 4-year-old David Harper, who suffered second- and third-degree burns but was pulled from the burning vehicle alive.
"People just go to into a higher place when they see something that's life-threatening," George Charles told the station. "They come outside themselves and they become their better self."
Firefighter goes in without safety protection
Firefighters normally arrive at a fire on a truck with their turnout gear on. Joe Hawthorne of Shirley, Massachusetts, was awakened at his home by his pager and realized a house just a few blocks away was on fire.
When Hawthorne arrived, children ran up to him and said their mother was inside the home and couldn't get out. Without any gear on, Hawthorne ran in and searched for her on the first floor, then went up some stairs.
"I heard her screaming and after I searched around some, I finally ... about five feet in, found her, grabbed a hold of her, gave her a yank and then tumbled down the stairs backwards," Hawthorne told WHDH of Boston on December 10.
Patricia LeBlanc, a 46-year-old mother of three, was listed in critical condition, the station reported.
Man drowns saving little girl
The family and friends of Allen Heck said he was kid who would do anything for anyone. His last act was one of heroism, helping to save a little girl from drowning. Heck was swept under by the current and drowned.
Witnesses told KPTV in Beaverton, Oregon, that Heck dove straight into the Cowlitz River when he saw a 9-year-old girl struggling in the water.
People were able to pull the girl to safety but Heck, 20, never surfaced. His body was found the next day.
Family members spoke with pride.
"My son is a hero, more than just a hero," Todd Heck told the station in July. "He should be remembered as a kid on their best day."
His sister was glad the girl was safe.
"A little girl is alive because of him. She gets to sit down and have dinner with her family tonight because of him," Shantel Huff said.
Mayor comes to woman's rescue
In August, Milwaukee's mayor became hero by coming to the aid of a woman who was involved in an argument on a Saturday night.
Mayor Tom Barrett had just walked out of the State Fair when a woman shouted for someone to call 911. The woman was arguing with a man police identified as 20-year-old Anthony Peters.
Peters attacked the mayor with a metal baton, according to police.
"Things got very, very ugly very, very quickly," Barrett told WISN of Milwaukee.
The mayor told the station that he had cuts on his head, was struck in the face and had a broken hand.
The station later reported Peters will go on trial on February 15.
Vacationing deputy lends hand to fall victim
A 25-year veteran of the Orange County, Florida, sheriff's department was on vacation in the mountains of North Carolina when a teenager fell 80 feet from a waterfall.
Jeff Doyle went to the aid of 16-year-old Jason Jackson, called 911 and stayed with the boy until he was airlifted to a hospital.
"The young man needed help and I just happened to be there," Doyle told WFTV of Orlando at a ceremony honoring his actions.
Jackson's injuries included two broken vertebrae, a broken ankle and a concussion.
"People say, 'You should've been dead.' I'm so grateful I get a second chance," Jackson told the station.
Officers save babies tossed from second floor
In Oklahoma City, Oklahoma, Anthony Pundsack and several other police officers helped rescue babies tossed from the second floor of a burning apartment building on December 5.
Pundsack told KOCO that he and his partner were driving through the area when they saw smoke. With two apartments ablaze, renters on the upper floor had to escape over their balconies.
Some dropped infants to the officers below.
"They were holding them by the arms. They were pretty frantic and pretty scared," he said. "At first, we thought they were going to drop them. We were yelling commands to them to just slow down, but they ended up dropping a couple. We were able to catch them, luckily."
Everyone made it out of the building safely, KOCO reported.