A victim of Saturday's shooting in El Paso died Monday morning at a Texas hospital, raising the number of fatalities in the massacre to 22, police said. The mass shooting -- one of the deadliest in modern U.S. history -- unfolded at a Walmart around 11 a.m. Saturday, as 21-year-old suspect, allegedly opened fire in the store, initially killing at least 20 and injuring another 26. Meanwhile in Dayton, Ohio Nine people have been killed in the second mass shooting in the U.S. in less than 24 hours, and the suspected shooter is also deceased, police said. Dayton police tweeted that an active shooter situation began in the Oregon District at 1 a.m. Sunday, but that officers nearby were able to "put an end to it quickly." Mayor Nan Whaley said officers shot the suspect within 60 seconds. Within that 60 seconds, the suspect killed 9 people and injured 27. All of the fatalities happened outside, police say.