CYPRESS, Texas - A 19-year-old man was killed Saturday after a trench collapsed on workers at a construction site, according to the Cy-Fair Fire Department. 

The incident happened at the corner of Mueschke road and Towering Cypress around 2 p.m. Officials said the crew was digging for a sewer system when the ground shifted and the trench caved in. 

The man's coworkers tried to save him but by the time firefighters arrived on the scene it was too late. The victim was apparently employed by a contractor called Principal Services Limited.

The man's brother came to the scene and had to be detained briefly after he tried to rush into the trench. 

Investigators are working to determine what caused the accident.