INDIANAPOLIS — An investigation is underway after two firefighters were struck by a vehicle on Interstate 65 early Saturday morning. The crash happened just after 4 a.m. on I-65 southbound between Kessler Boulevard and 38th Street. According to the Indianapolis Fire Department, the firefighters were helping people get out of a vehicle that had run off the interstate and into a grassy area near mile marker 117. IFD was wrapping up its duties and waiting for state police to arrive at the scene when the firefighters were struck. Officials indicated that one fire vehicle was in the far right lane and positioned at an angle to block oncoming traffic. An IFD engine was also stationed in the area. Both fire vehicles had their lights on when a motorist drove through the closed crash scene, speeding along a gravel berm. The motorist, who was driving a black 2013 Nissan Altima, struck the car that IFD was first called to the area to assist. After hitting the vehicle IFD had been dealing with, the driver of the Altima ran into two IFD firefighters. The crash sent one of the firefighters airborne. Another firefighter was pinned beneath the motorist's vehicle during the crash. Officials at the scene freed the firefighter who was trapped under the car and called emergency personnel to request additional resources. Both firefighters were transported from the scene to Eskenazi Hospital. One of the firefighters was checked at the hospital and released. The other, according to IFD, was admitted with serious, non-life-threatening injuries. Per IFD, the firefighter that was checked into Eskenazi was alert and oriented at the hospital. In a press release, Indiana State Police later reported that the driver of the Altima, 30-year-old Christino Rodrigo Alva of Pueblo, Mexico, was arrested. Alva now faces the following preliminary charges: Operating while intoxicated resulting in serious bodily injury — a Level 5 Felony Operating while intoxicated endangering a person — a Class A Misdemeanor Operating while intoxicated with a BAC at or above .15 — a Class A Misdemeanor Operating without ever having received a license — a Class C Misdemeanor Marion County Jail logs indicate Alva is now on an ICE detainer. He is due to appear in court on Sept. 10. As of this article's publication, no additional information on the incident had been made available.