A crash at the Gran Turismo Polonia involving a Koenigsegg CCX injured 19 people, four of them seriously, who were watching the start of the rally race. The cars were on their way to Poznan after leaving from Gdansk.

The Gran Turismo Polonia allows owners of exotics to race about on public streets and private tracks throughout Europe.

The driver of the car itself is okay but the car itself is wrecked, according to Lukasz, who sent in the tip:

The car was registered in Sweden. The driver, Morten N. lost control of the car shortly after launching it from the start line. The car then spun and hit the curb ending up hitting a group of spectators.

The yellow CCX, seen here leaving Gdansk, is believed to have been the one involved in the crash:

We'll update you as we have more information.

UPDATE: Lukasz has sent in some more information:

From the relation of the eye witness and police it looks like an evident error of the driver.
The accident took place on a 400m straight road just after the start line, the road was closed for the public by the organisators and the spectators were dissociated by the barriers. The accident happened around 16:00 CET. The car struggled to stay in the straight line just after he launched from the start line. The driver lost control of the car and hit a curb and the barriers at big speed.
All the injured people were taken to the hospital. The driver, has been interrogated by the police, he was sober when the accident happened.
The Gran Turismo Polonia is an event held in Poland every year around summer when you can see the fastest and most exotic cars. This year there were 175 participants, mostly Ferraris, Porsche, Lamborghini, McLaren, Audi etc. This years edition is the 9th.
The eye witness say, that the driver probably wanted to impress the crowd. He accelarated really hard from the start line. He wanted to show off but unfortunately he lost control of the car, started to spin and eventually hit the curb, the barrier and ended up on the shoulder. Because the car has a low front it basically made all the crowd fly in the air. People were flying all over the place. The speed was so high that people had no chance to move away and escape.
Police investigation will explain if its the drivers fault and if the organisators are also guilty for not sufficient security for the audience during the event.

Lukasz also shot this video of the car right before the accident, and it doesn't appear as if the driver knew what he was doing:

H/t to Lukasz, Brian, and Ian!