The Jupiter Police officer killed Sunday while working a presidential motorcade crossed several lanes on Interstate 95 and pulled in front of a pickup truck in an attempt to block traffic, according to a preliminary investigation released Monday.

Bruce Edwin St. Laurent, 55, was heading southbound on I-95 when he tried to stop traffic and was struck by a white Ford F-150 pickup driven by West Palm Beach resident Susan Holloway, 56, according to the Palm Beach County Sheriff’s Office.

St. Laurent was taken to St. Mary’s Medical Center shortly after the 4:45 p.m. crash and was declared dead. Holloway was not injured.

Sheriff’s investigators said Monday that neither alcohol nor drugs played a part in the crash. No charges have been filed against Holloway as the full investigation, which could take months, continues, a sheriff’s spokeswoman said. A more-detailed incident report by the Florida Highway Patrol is expected to be released this week.

Preliminary reports by the sheriff’s office said Holloway was “attempting to accelerate to a safe speed to merge with southbound traffic,” and “attempted to avoid the crash by making a heavy brake application.” The report also said St. Laurent “moved into the path of travel” of Holloway’s truck.

It’s unclear how fast St. Laurent and Holloway were traveling.

No one could be reached Monday at an address listed for Holloway and calls made to her home were not answered.

According to the report, St. Laurent, a 20-year law enforcement veteran, had his emergency lights on when he moved his bike “at an angle toward the right, crossed several lanes of traffic” and entered the southbound on-ramp from 45th Street “in an effort to stop traffic from entering I-95.”

St. Laurent was thrown off his motorcycle when Holloway crashed into it with the front of her truck. His motorcycle was caught underneath Holloway’s truck as the two vehicles slid to a rest.

President Obama was heading to the Palm Beach County Convention Center on Okeechobee Boulevard in West Palm Beach for a campaign stop. He was notified of the crash during his flight from Palm Beach International Airport to Washington, said White House Press Secretary Jay Carney, who added that the president’s thoughts and prayers were with the officer’s family.

Carney told CNN that the crash happened near the front of the motorcade and Obama did not see it. CNN also reported that one of its photojournalists who was in the motorcade said this presidential caravan was longer than normal. According to CNN, the motorcade was made up of three buses, including the president’s campaign bus, along with the normal number of SUVs. Motorcycle police are usually used as escorts and handle intersection control for motorcades, CNN reported.

St. Laurent was the second law enforcement officer killed in Palm Beach County while working a motorcade for a president or presidential candidate.

In 1992, Palm Beach County Sheriff’s deputy Kevin D. Mathews died while providing a motorcycle escort for Democratic presidential hopeful Paul Tsongas. He was hit by a limousine in Palm Beach and died at the scene. Mathews was honored this May as one of 14 county deputies who died in the line of duty.