By Alexa Ball
Seven United States Marines were killed Wednesday when two helicopters collided near the Arizona-California border officials said, according to Fox News.
The crash occurred midair around 10:30 p.m. during routine training operations Marine Corps Air Station Yuma Base Commander Col. Robert Kuckuk said, according to CNN.
The training took place in southeast California over the Chocolate Mountains, according to Fox News.
Authorities are investigating the cause of the collision, which could take months to complete, so far it does not appear that weather was a factor, according to CNN.
The names of the Marines killed will be released after their family members have been notified, according to Fox News.