An 18-year-old Rockville youth, critically injured Tuesday night when the car he was driving careened off a curve on Avery Road and struck a tree, died last night at Suburban Hospital, Montgomery County police said.

Scott Bennett Bolon, of 4235 Norbeck Rd., received broken arms, legs and facial bones in the 10:45 p.m. accident that also injured two other Rockville teen-agers, police said. Bolon was pronounced dead shortly after 8 p.m. last night, they said.

Kelvin Oie, 16, who was a passenger in the back seat, remained in critical but stable condition at Suburban Hospital with facial injuries, hospital officials said last night.

The carload of five teen-agers was returning from an evening of bowling and dining when Bolon lost control of the car on a curve in the 14700 block of Avery Road, according to witnesses and police. Police said Bolon was exceeding the speed limit but that the exact cause of the accident was unknown.

Bolon and his passengers, Oie, Aaron Weitzman, 18, who was admitted to Shady Grove Adventist Hospital but released Thursday, Kelly Hsu, 18, and Jane Nguyen, 17, were all wearing safety belts when the crash occurred, police said.

Bolon, Hsu, Nguyen and Weitzman graduated from Rockville High School this month and Oie will be a senior there in September, officials said. Nguyen said that none of the five had been drinking at the time of the accident.