Relatives and friends of eight people killed while watching an illegal street race in Maryland have erected memorials of flowers, crosses and candles on the site.

The spectators died when a car unconnected to the race plowed into a crowd on the isolated stretch of highway in suburban Washington D.C. early Saturday morning. The crowd had spilled into the roadway after the two cars that were racing sped off. Police say the other driver may not have been able to see the people in the road because of darkness and the smoke from spinning tires.

A community official says illegal street racing has been a problem for more than 20 years on the highway. Authorities say it's tough to crack down on the underground races because the people who arrange them are well-organized and have lookouts for miles.