COLORADO SPRINGS, CO -- Law enforcement officals are investigating two separate motorcycle crashes that occured late Friday night.

The first happened just after 8 p.m. on I-25 near milepost 136 in El Paso County.

The Colorado State Patrol said a 2009 Harley Davidson was traveling northbound on the highway in the right lane when the driver lost control.

The motorcycle then traveled off the left side of the road and collided with a guard rail, killing the driver.

Authorities said the driver is a 53-year-old man from Colorado Springs, and added he was not wearing a helmet at the time of the crash.

They said they are investigating to see if alcohol and speed contributed to the crash.

Then, fewer than two hours later, a second fatal motorcycle crash occured at the intersection of Rangewood and Randall in Colorado Springs.

The Colorado Springs Police Department said two motorcycles were driving southbound on Rangewood when a green sedan turned left in front of the motorcycles.

Officers said the driver of the green car then left the scene of the crash.

They said one of the drivers had a passenger on the back of his bike, both of whom were treated for their injuries at a local hospital.

As for the other driver, he died as a result of his injuries.

Officals said both men are active duty soldiers stationed at Fort Carson, and added the 19-year-old man killed was from Boston.

Police are asking anyone with information about this crash to call them at 444-7000 or Crimestoppers at 634-STOP.