CORPUS CHRISTI, Texas — Firefighters from around the country are in Corpus Christi this week training for a variety of worst-case scenarios.

For construction workers who often have to work in deep trenches, one of the many dangers they face is the possibility of a trench cave in.

OSHA data shows 23 construction workers were killed in trench collapses in 2016, exceeding the combined total from 2014 and 2015. Even a trench collapse five feet deep can kill or seriously injure a worker.

"People don't realize they're being dug all over the city all the time," said Battalion Chief Frank Solanski of the Corpus Christi Fire Department. "It's a lot more frequent than people realize."

Solanski said the city hosts the training for fire personnel from around the country. Trenches are dug and reinforcements of steel are placed to keep the sides from collapsing under their own weight or if water or another outside factor is affecting the trench.

"Often times in these things, someone gets hurt and everyone just surrounds and ends up getting themselves in trouble as well, and that's what this training is about," Solanski said.

According to OSHA, one cubic yard of soil can weigh as much as a car, so even if someone is only buried waist deep, it can be a potentially life-threatening situation.

Firefighters who go through the training said it teaches them what to do if they are the first on the scene.

"60 to 80-percent of the pople that get involved in a trench collapse are secondary people," CCFD Capt. Thomas Cruz said. "I want to go help my friend, the trench collapsed more, then I fall in and become part of the problem as well."

The four-day training shows firefighters how to rescue someone by rebuilding the trench with shoring and support to keep the walls from falling further and then digging the victims out. The training continues Friday.