(CNN) -- At the start of the evening dinner rush on January 10, a group of 13 is seated at an Applebee's in Mason City, Iowa. Their waitress is new. She is nervous. She has never served a big group before but after a little reassurance she is ready.
The 13 men and women, ages 25-60, are dressed in flight suits from University of Iowa AirCare. They have just attended a memorial service for three colleagues killed in a medical helicopter crash on January 2 and have stopped for dinner before the long drive home. Dr. Azeem Ahmed, medical director of the University of Iowa AirCare program, said the deaths had hit the Northern Iowa emergency responder community hard.
Russ Piehl and Shelly Lair-Langenbau, along with pilot Gene Grell, were killed just minutes after climbing into a Mercy Medical Center North helicopter to pick up a patient. Although the cause of the crash is not known, the Des Moines Register reports the helicopter hit the ground and burst into flames just 15 miles away from the hospital from where it had been dispatched. Radio Iowa said Grell was looking forward to being a "husband in the near future." The paper described paramedic Piehl as a dedicated professional with a sense of humor. Nurse Lair-Langenbau was described by WHOtv.com as a "hell of a nurse" and dedicated mother to her two young daughters.
More than 1,000 people including emergency responders, members of the public and family attended the service.
"It was somber, but uplifting," Ahmed said. "It helped us all with the healing process."
As the group finished their meals their waitress told Ahmed their bill will be "very small."
"What do you mean?" Ahmed asked.
The waitress handed the doctor a folder. Inside was a note on a napkin, written in capital letters.
"For all you do and in memory of your team mates ... This meal is on us."
Ahmed said after reading the note he stood up and addressed the group, explaining what had just happened. Then he passed it around. Some had tears in their eyes.
"We were very moved and humbled," said Ahmed. "We were overwhelmed."
Jennifer Allen, Applebee's associate manager, said the entire staff was overwhelmed, "in a good way." On the drive home Ahmed said the conversation naturally gravitated toward the note. Each person, Ahmed said, committed to paying the good deed forward.
Ahmed posted a photo of the note and a short caption to his Facebook page and on the Facebook page for University of Iowa AirCare. It received more than 2,000 shares, 12,000 likes and 500 comments. When asked why he shared it he said there were three reasons.
First, he wanted to recognize the person, who wished to remain anonymous, in some way for her or his kindness.
Second, he wanted to let emergency responders know what they do makes a difference and for them to feel the same support.
Third, he wanted to honor those who died by motivating others to pay it forward. "It's motivation for myself and everyone who sees it to do something similar," Ahmed said. "In the end, the people who died, this is the best way to honor them."