OCALA, Fla. -

A Florida Highway Patrol trooper and two others were killed after being struck by a vehicle Saturday afternoon while standing alongside Interstate 75 near a traffic accident, authorities said.

FHP officials said veteran trooper Chelsea Richard died when she, tow truck driver John Duggan and pedestrian George Phillip were hit by a pickup truck about 1:40 p.m.as they stood on the shoulder of the highway after a two-car crash in Marion County.

Richard, 30 and Duggan, 57, were pronounced dead at the scene. FHP said that 52-year-old Phillip later died at a hospital.

Richard initially arrived on the scene of a two-car crash on I-75 southbound. Both cars involved in the crash were on the shoulder. Shortly afterward, authorities said, a pickup truck traveled onto the shoulder and struck the trooper's vehicle, the trooper, Duggan and Phillip.

FHP said investigators are going through physical evidence and witness statements. Authorities said charges are pending completion of the investigation, which could take several months.

Richard was a nine-year veteran of FHP, and the 45th FHP trooper killed in the line of duty.

Funeral arrangements for Richard were still being worked out by her family.