A measles outbreak in West Texas has topped 120 cases and resulted in the first U.S. death from the illness in a decade.

At least 124 cases have been identified in Texas since late January, mostly among children and teenagers who are unvaccinated or whose vaccination status was unknown.

A child in West Texas has died of measles, state health officials said on Wednesday, the first reported U.S. death from the highly contagious disease in a decade, as a Texas outbreak has grown from a handful of cases to more than 130 across two states.