All they wanted to do was impress some girls.

Right after work on Monday afternoon, Mohsen Modjtahedi, 20, and his friend Arya Asgarynejad, 20, got ready for a night out with friends in south Orange County.

Asgarynejad borrowed his father's Mercedes that morning so the two would have a nice car to pick up Tara Moghadam, 17, who had started dating Modjtahedi.

They picked her up and met up with another girl, Kara Jafarinia, 18. From there, it was In-N-Out Burger for some food and a tragic decision.

Ghassemian and his BMW M3

An impromptu street race ensued around 8:30 p.m. Monday, leaving Parees Ghassemian, 18, of Laguna Niguel dead and Asgarynejad, 20, of Irvine arrested on suspicion of manslaughter and operating a vehicle with gross negligence causing death.

The two girls who joined them are both at Mission Hospital. Modjtahedi suffered no injuries.

Just days ago, Gov. Arnold Schwarzenegger signed into law stronger enforcement against street racers. It requires a driver convicted of engaging in a motor vehicle speed contest that causes injuries be punished by time in jail or a fine up to $1,000.

"Law enforcement's frustration with racing on the public roadway is not only that these youths don't recognize the harm to themselves, but also that they fail to recognize the danger they pose to the rest of the motoring and pedestrian public," said Capt. Jack Anderson, the sheriff's commander of South County Operations. "They don't look at the consequences of behavior."

Modjtahedi said no one in the group had been drinking or using drugs. He said the challenge arose when Asgarynejad and Ghassemian started talking about racing.

The group decided to go for it. Ghassemian and the two girls got into his prized possession – a 2004 BMW M3. Modjtahedi and Asgarynejad got into the Mercedes CLK 55.

They roared down La Paz Road between 80 and 90 mph east toward Paseo de Valencia. Modjtahedi became frightened.

"I was trying to tell him not to race," he said. "I told him, 'It doesn't matter who wins.' "

But it was too late.

"I heard the tires screech," he said. "I checked the side mirror, and I saw the car flying and hit the water hydrant and then the wall."

He called 911. Asgarynejad made a U-turn.

When they got to the car, it was lying upside-down in the middle of La Paz.

"I tried to talk to (Ghassemian), but he was dead," said Modjtahedi of the youth he had just met that night. "All I heard was Tara screaming for help."

On Tuesday, close friends and family came to pay their last respects. More than 30 teens went to Mission Hospital to hold a vigil for the two girls in the morning. In the afternoon, they arrived at the crash scene and remembered Ghassemian.

"He was always happy and always there for everyone," said Heidi Radmanesh, 17, of Laguna Niguel. "He kept everyone's secrets and was everyone's friend."

Flowers and balloons were placed at the site.

Rooshi Yaghobi, 25, wore a necklace with the Farohvahar – the Persian symbol of monarchy. It was found at the crash site – and belonged to Ghassemian.

"How do you find this and nothing else?" she asked through tears. "I hope it will make all these boys stop using the cars as toys. Your life isn't replaceable."

The people involved

Age: 20
Residence: Irvine
Role: Driver of the Mercedes-Benz. Asgarynejad is in custody on suspicion of vehicular manslaughter and operating a vehicle with gross negligence causing death.
Background: Student. Works at Target in Irvine

Age: 20
Residence: Irvine
Role: Rode with Asgarynejad. Not arrested.
Background: Student at Orange Coast College and editor at Salaam, Persian television station in Santa Ana.

Age: 18
Residence: Laguna Niguel
Role: Driver of the BMW. Was killed when he lost control of the vehicle and crashed.
Background: Senior at Capistrano Valley High School. Worked at his family's pizza parlor.

Age: 18
Residence: Laguna Hills
Role: Was a passenger in Ghassemian's BMW, sat in the front passenger seat. She suffered a broken arm and fractured pelvis. Mission Hospital officials list her in fair condition.
Background: Student at Irvine Valley College.

Age: 17
Residence: Ladera Ranch
Role: Was a passenger in Ghassemian's BMW. She sat in the back seat. CHOC at Mission Hospital listed her in critical condition Tuesday.
Background: She is working on her GED and getting her real estate license.