David Scherff spent August 27 on his boat in the floodwaters of Katy, Texas, rescuing more than 50 people throughout the day. But that night, he lost his closest passenger.
Frank the English Bulldog is still missing, and the #FindFrank campaign has started to get the word out to anyone in the Katy area who might spot Scherff's sidekick.
"He's more than a best friend," Scherff said about his companion, who he bought as a malnourished pup over two years ago.
After taking part in the rescue of a family with two dogs of their own, Frank was at the bow of Scherff's 19-foot powerboat when it hit a submerged object - possibly a car.
Frank fell into the raging waters, and one of the rescuers took action.
Tim Donovan is a Marine who joined the group that day to help their efforts. Scherff said Donovan saw Frank fall into the water, and didn't hesitate to jump into action.
In a series of text messages, Donovan reflected on his experience in the water. He and Frank were both swept under a railroad bridge along I-90 in Katy, which was when he lost sight of Frank.
Donovan spent two and a half hours alone before his distress signals were answered by a group of firefighters. He said he needed to use all of his survival skills to stay alive, but still wishes he could have gotten to Frank.
Scherff said he's hoping for a miracle - that Frank will be able to return to his spot at Scherff's side. Still, Donovan has faith the English Bulldog will make it back home.
"I have a feeling," Donovan said, "that Frank is alive. He is a Bulldog, the Mascot of the US Marine Corps; and that makes him a Marine like myself. If I could get out, so could he."
To help spread the word about Frank, tweet with the hashtag #FindFrank on Twitter, or follow the link here to reach the Facebook page.