Three people were killed overnight Sunday after a gathering in a short-term rental turned deadly near Houston, Texas.

Harris County Sheriff Ed Gonzalez said deputies responded to an emergency call around 2:15 a.m. at a suburban neighborhood in Katy, Texas, just 30 miles (48 kilometers) west of Houston.

“It was a very active scene. It was very chaotic upon the deputy’s arrival,” Gonzalez said at a Sunday morning press conference.

Gonzalez estimated about 10 to 20 young people were gathered at a short-term rented home before the shooting started. The sheriff did not yet know if there was one or more people who opened fire, but there was evidence it happened inside and outside of the home sometime around 2 a.m.

When the first deputy arrived, two people had already died at the scene and another person would later be confirmed dead at a hospital. The victims are thought to be in their 20s, but no exact ages or identities were confirmed Sunday morning.

The sheriff’s office said they were still piecing together information and were seeking information from the public to find those involved in the shooting.