In California in the early 1980s, a cracked tooth sent Mike Williams to the dentist's office.
When Williams asked to see the tooth, the dentist said he had a mirror but that there was no camera or anything to show people the insides of their mouths. So, Williams invented one: the first intraoral camera.
His invention was a big success, and it led to other medical technology ventures that made him millions of dollars. Williams' career as an inventor and entrepreneur took off, but it wouldn't last.
"The real estate market destroyed a lot of my financial capabilities, and my home went into foreclosure [in 2009]," Williams tells NPR's Robert Smith. "I had a group that defrauded me in Florida, took about $2.5 million from me in a scam, and it just kept going and kept going and I couldn't stop it."
His world was crumbling. Then his wife asked for a divorce.
"I packed my car, told my kids to come and get what they wanted and I basically hit the streets," he says.
The successful inventor had become homeless.
For a while, Williams lived out of his car and kept a journal on a laptop. Once he fell behind on the car payments, he took shelter in a dumpster. The situation hit him hard.
"I found out that I was really nothing, and that was very hard for me to grasp; the fact that no one wanted me around," he says. "I was something nobody wanted to see or be involved in, and that crushed me."
One night last August, Williams was sleeping in a Sacramento park when two men began kicking and beating him. They beat him until he passed out, taking his belongings and leaving him with severe injuries.
Williams walked to the emergency room. He didn't have health insurance, and he says he waited for hours before seeing a doctor.
"Little did I know that that beating would be the beating that changed my life," he says.
A Second Chance
Williams' injuries eventually led him to Dr. Jong Chen.
He went to Chen complaining of pain in his lower abdomen; it turns out he suffered prostate damage that required surgery. Before the operation, the two men struck up a conversation, and Chen asked him how he became homeless and what he did before that.
"And I started telling him the story," Williams says. "And I said, 'As a matter of fact, I'm the inventor of that little wire catheter you're using.' "
Chen thought it was a waste that an inventor like Williams was on the street, so he devised a way to help him. He later called Williams at a local Salvation Army shelter and asked to take him out to breakfast.
"He said 'I want you to bring your patents. I want you to bring whatever you're working on,' " Williams says.
They went to breakfast, and Williams talked of about his idea to invent a secure, safe place for the homeless and people that are displaced in society.
"I want to give them a safe place to live," he says he told Chen.
Williams came up with the idea while resting in one of the only safe places he could find: a dumpster. He'd even drawn up the plans for a self-contained survival pod a 6-foot by 6-foot structure with a single bed and a chemical toilet.
Chen signed on, and they formed a company to start working on a prototype pod. They also envision other applications FEMA could use them for emergency housing, and airports could rent them to travelers with long layovers.
All of that got started with an unusually generous contribution.
"To me, a patient is a patient, no matter what kind of status [they] have," Chen says. "They need the help, [and] we can give him the help."
Chen got Williams out of the shelter and back on his feet. He helped him get an apartment, new clothes and treated him to meals when the two would meet.
Williams says he is humbled by the second chance he's been given by the generosity of one man, and says it's people like Chen who are truly helping people.
"[Dr. Chen] is truly an amazing man," Williams says. "I'm just telling you, [he] is the example for America."