The Florida Highway Patrol had a busy weekend responding to four crashes in the Florida Keys -- one of them a fatal hit-and-run.

Phillip Brown, 30, of Key Largo was killed at about 2:15 a.m. Saturday while crossing U.S. 1 at Tarpon Basin Drive near Mile Marker 101, troopers say. The driver who struck Brown fled the scene.

"[Brown] was struck by what we believe is a gold-colored Pontiac Sunbird or possibly a Honda Civic," FHP spokesman Alex Annunziato said.

Troopers searched for the northbound car, but had not found it as of Monday. It is likely to have extensive front-end damage to the grill, headlights and hood, Annunziato said.

It was unknown whether there were passengers in the car. Brown was with two other pedestrians when he was hit.

In an unrelated crash, a pedestrian who had just left the Tom Thumb convenience store at Mile Marker 88.8 was struck by a car at about 9:30 p.m. Sunday, troopers said.

Robert Patterson, 74, of Illinois, was struck by a 1996 Ford driven by 18-year-old Priscilla Firth of Virginia, Annunziato said. Both were in the Florida Keys for vacation, he said.

Patterson was airlifted to Ryder Trauma Center in Miami, where he was listed in stable condition Monday.

Firth, who remained on scene and was cooperative with troopers, was not cited. Neither drugs nor alcohol were believed to be a factor in the crash, Annunziato said.

There also were two non-fatal, two-vehicle crashes on U.S. 1, beginning with one at 7:30 p.m. Friday at Mile Marker 14 in the Saddlebunch Keys. One person was airlifted to a Miami hospital, and two others were taken to local hospitals.

Six people were injured in a crash at 3 p.m. Saturday at Mile Marker 21 on Cudjoe Key, Annunziato said. Two of the injured were airlifted to a mainland hospital.

The names of those injured in the two Lower Keys accidents were not available Monday.

Troopers are asking that anyone with information about the hit-and-run in Key Largo call Crime Stoppers of the Florida Keys at 800-346-8477.

alinhardt@keysnews.com