A Texas measles outbreak has doubled in the last week to 124 cases, state health officials said Tuesday, a day after they warned a person infected with the highly contagious disease had traveled from the outbreak zone.

LUBBOCK, Texas (AP) — A person who was hospitalized has died from measles in West Texas, the first death in an outbreak that began late last month. Texas Tech University Health Sciences Center spokesperson Melissa Whitfield confirmed the death Wednesday. It wasn’t clear the age of the patient, who died overnight.

A child who was not vaccinated has died from measles in West Texas. It's the first death in an outbreak that began late last month and the first from measles in the U.S. since 2015.