UT's fire could have made it tough to use your cell phone on UT's campus Friday.
US Cellular tells us phone calls were blocked for three or four hours because so many people tried to phone home, or their friends, or 911.
The pros tell us it is common anytime there is an emergency.
Cell towers are designed to handle a volume of calls typical of the busiest day.
On big events when there's expected to be an abundance of calls like a UT game, a cell truck is brought in to handle the extra load but companies say they can't plan for spontaneous emergencies.
"In an emergency or natural disaster really depending on the load on the system, its really difficult to predict when you might get blocked because its an abnormal situation," said Dana Dorcas from U.S. Cellular.
When it comes to emergencies, make sure you dial 911 first.
Then if you can't get through to talk to your family try texting.