INDIANAPOLIS, Ind. — An Indianapolis family says their glass sink exploded without warning, and they want to warn other people about the hidden household danger.

The Keller family, like many others, decided to tackle a home renovation project on their own last year. As they remodeled their bathroom, they opted for a blue glass tempered glass sink they found on Amazon.

“I had no idea that this was a possibility, I was just excited to have a beautiful sink,” Shelly Keller said.

Keller said she was cleaning the bathroom when suddenly, the sink exploded.

“I heard what I initially thought was a gun fired right next to my head, and I screamed,” Shelly Keller said.

“It sounded like a bomb going off,” Rich Keller said.

Afterwards, shards of glass were left over. Shelly Keller was covered in glass pieces and dust, bleeding, but did not suffer any major injuries.

“When I was bent over my hair was covering my face, and that’s what saved my face,” Keller said.

Afterwards, Rich Keller started researching and filed a report online with the U.S. Consumer Product Safety Commission, or CPSC.

“I’m an engineer so what’s the root cause? We’ve got to figure it out,” Keller said. “Just to make people aware, that’s the biggest thing.”

CBS4 Problem Solvers wanted to know what happened in this case, and what consumers needed to know, so we took the pieces of the broken sink to Mike Fultz with Service Glass of Indianapolis.

The key to this case is the fact that the glass was tempered, a process used on most glass these days, according to Fultz. Tempered glass is designed to break into small pieces, so it actually should explode if it breaks.

“The alternative would be a float glass that breaks in big shards, which could really cut you,” Fultz said. “That tension releases, and that’s why it breaks like that.”

When CBS4 showed Fultz the leftover pieces, though, he said they seemed to be larger than usual, due to a backing which was painted to give the sink its blue color and design.

“This is a chunk instead of a small fragment,” Fultz said. “That does seem a little more dangerous.”

On the CPSC website, CBS4 Problem Solvers found hundreds of reports about tempered glass explosions. Many of them were about shower doors, but at least five filed this year alone were for glass vessel sinks, like the Kellers’.

In one report, the photos of the leftover glass looked very similar, with larger chunks instead of small pebbles.

Some of the companies producing the sinks responded to the reports, saying an explosion can be caused by things like “improper mounting” and misuse.

Fultz said another possible culprit could be nickel sulfide, a compound that is sometimes created during the tempering process.

“It is possible over time that that nickel sulfide actually starts to work its way out and can cause that glass to break for no apparent reason,” Fultz said.

The CPSC has not issued any warnings about glass vessel sinks, but a quick search online shows they are now a common product.

For the Kellers, any explanation leads them to the same conclusion: had they known their sink would explode if it broke, they would never had bought it in the first place.

“I just want to be able to warn other people,” Shelly Keller said.

You can find reports, or file one, on the CPSC website here.