A 156-page grand jury report released Tuesday by the Suffolk County district attorney says poor limo construction and a poorly designed traffic light played a major role in the East End crash that killed four women on a winery tour last year.

The limo was carrying eight women who were touring wineries when it was broadsided by a pickup truck in an intersection along Route 48 in Cutchogue.

Brittany M. Schulman, 23, of Smithtown; Lauren Baruch, 24, of Smithtown; Stephanie Belli, 23, of Kings Park; and Amy R. Grabina, 23, of Commack, were killed in the crash. Four other women and the limo driver were hospitalized.

District Attorney Thomas Spota said before issuing the report that a special grand jury reviewed thousands of documents, heard testimony from 47 witnesses and looked at nearly 200 exhibits.

According to the report, stretch limousines are poorly constructed, not well-regulated and have inadequate protection for passengers. The car was originally built as a Lincoln Town Car, which was "cut in half and then stretched to 120 inches to accommodate 10 occupants."

Spota says there were no safety checks performed on the vehicle before the July 2015 crash.

"They didn't know they were putting their trust in a vehicle that was untested," says Spota.

In October, criminal charges against the limo driver, Carlos Pino, were dropped. The District Attorney's Office is appealing that decision.

According to the report, the traffic light that is now at the Route 48 intersection is still not protecting drivers from the possibility of another similar crash. The report says the only way to avoid another crash is to install a left turn signal in both directions.

The report also mades several recommendations, including making U-turns illegal for limos anywhere in the state, requiring stricter licensing and training for limo drivers similar to that of bus drivers, and changing the legal definition of criminal negligence to apply to professional drivers who cause fatalities in crashes where the professional driver is at fault.

"If nothing changes, there is bound to be another tragedy," the report states.