There were dozens of complaints to the Consumer Product Safety Commission from people who lived through similar experiences. Our investigation found out what's causing it.
San Jose resident Kathy Kavianian showed us how far the glass from her shower door exploded one summer night. Her husband, Kevin, took video of the aftermath.
"As we were waking up, we heard this massive boom. You know this huge sort of? like an earthquake," said Kevin.
Both Kathy and Kevin feel lucky they weren't nearby when the explosion occurred. They're reminded of this every time they take a shower.
"Oh, I'm pretty scared. I am very scared. Every day I make sure I leave the phone here by the shower door now," said Kathy.
There are many videos posted on YouTube from people whose shower doors also combusted without warning. In all, we found 57 complaints to the Consumer Product Safety Commission about exploding shower doors from various brands since 2011. One person found his shower door had severely fractured, but not yet crumbled. So he had to finish the job.
Injuries have occurred in more than one out of three incidents reported to federal regulators.
A 77-year-old unidentified woman wrote online, "Our 17-month-old rimless glass sliding shower door exploded all over me while I was in the shower. The result was four severed tendons in my hands."
Another wrote, "One deep stitch and six outside stitches on the right leg and one stitch in the left leg and other cuts cleaned."
Tarek Zohdi is a mechanical engineering professor at UC Berkeley. He encourages everyone to check the area near the hinges of your shower door for any fractures and nicks. He told us, "What happens is with a shower glass door you're banging against it, you're moving it around like a hinge. The crack will start to extend itself and it will start to grow in this pattern and keep growing and growing and growing until it separates the two surfaces apart."
Shower doors are made of tempered glass. A demonstration by Glass Plus in San Francisco shows that tempered glass is made to break into small pieces--something much preferable to more dangerous, larger and sharper pieces.
Zohdi says if your shower door explodes while you're taking a shower, don't panic. He said, "There is no reason to run out and panic. What you should do is very carefully take a towel, place it over the crumbled pieces of glass."
He says tempered glass is doing what it's supposed to do when it crumbles into small pieces. The Consumer Product Safety Commission declined to be interviewed, but says it sees no need for a recall. The Kavianian's disagree.
"We're very careful opening and closing doors, so there's no reason why this thing should spontaneously blow up like this," said Kevin.
We contacted Old Castle -- the company that supplied the shower door to Kevin's contractor. Old Castle agreed to pay for the replacement cost of Kevin's shower door, but had no comment beyond that. The couple still sees a larger issue.
"I think the government, somebody, they should do something to make this, prevent something like this. This should not happen to anybody," said Kathy.
The number of injuries cited in this report were based on people who actually bothered to call federal regulators to file a complaint. Based on information received from hospital emergency rooms, regulators estimate that more than 2,500 people were treated for injuries related to shattered shower doors from 2010 to 2012.