WHEAT RIDGE, Colo. The Wheat Ridge Police Department announced on Wednesday that it has completed its investigation into an August crash on Interstate 70 that left a newlywed couple and the bride's mother dead and determined that a crime was not committed. The crash happened around 8:21 a.m. on Aug. 15 in a construction zone between Ward Road and 32nd Avenue, according to Eric Kellogg, division chief of the Wheat Ridge Police Department.A semi-truck which was carrying large, blue plastic piping was traveling east along I-70 when it flipped over. As it crashed onto the road, the piping came off the truck and spilled onto the eastbound and westbound lanes of I-70, causing at least three other vehicles to crash, Kellogg said.Three people inside one of those vehicles were killed. Family members identified them as Ruben Rodriguez, 33, Juliana Rodriguez Plata, 37, and Juliana's mother, Luz Melba Martinez. Juliana's father, Carlos Joaquin Plata, and the couple's 1-year-old son, Daniel "Danny," were also in the car and were injured in the crash.The driver of the semi-truck was also injured, Kellogg said.In its announcement Wednesday, Wheat Ridge PD said it conducted its investigation alongside the First Judicial District Attorney's Office. The two determined that there was "no probable cause that a crime was committed that day."The police department said its Crash and Traffic Team reviewed data, videos, environmental conditions of the interstate and the semi-truck's inspections before making its decision.An inspection performed in July found no issues with the vehicle, according to Wheat Ridge PD.An additional inspection was performed 40 minutes before the crash at a Colorado State Patrol Port of Entry weigh station along I-70. Wheat Ridge police said that inspection found the vehicle was 8,000 pounds underweight, was "over-strapped" for the pipes it was carrying and did not have brake issues. Data from the Black Box on the vehicle showed the semi-truck was traveling at a rate of 59 mph in a 60 mph zone. Wheat Ridge police said there were no signs of impairment or intoxication from the driver, and the trucking company was "fully compliant" throughout the investigation. Wheat Ridge PD called the incident a "tragic, heartbreaking accident" and said it has talked with the victims' family about its findings. The investigation is now considered closed, according to the department. After the crash, the Colorado Department of Transportation (CDOT) implemented safety changes to the construction zone, lowering the speed limit from 60 to 55 miles per hour and installing new signage.