For the first time ever, RTD is going to replace parts of its light rail tracks.

That means some service will be down for 10 days.

RTD is using a $2.5 million FASTER transit grant from the Colorado Department of Transportation to update its aging infrastructure, starting with its oldest tracks and other components downtown. According to a press release, it’s the first of several projects coming in the next few years. Crews will be working in the area adjacent to the intersection of 19th and California streets.

Service will be suspended on the D, F, H and L lines from the 30th & Downing stop to the Theatre District/Convention Center station. RTD will provide charter buses in lieu of those routes. The work will also affect buses and car traffic. All lanes will be closed on 19th Street between Stout and California streets, and on California Street between 18th Street and Broadway. There will be detours and temporary stop locations for the 28, 38, 43, 44, 122X, FF7, Free MetroRide and RX.

Work begins at 8 p.m. Friday and runs through 3 a.m. Monday, Sept. 24.