Four people have been sent to hospital after they were involved in a serious crash on Crowchild Trail in southwest Calgary on Tuesday night.

At about 11:30, emergency crews responded to the scene of a single vehicle crash at 50 Avenue and Crowchild Trail S.W.

Firefighters quickly discovered that two of the occupants had been ejected from the vehicle as a result of the crash, and two people were trapped inside.

All four patients, a 21-year-old male driver, a woman and two other men, all in their 20s, had sustained serious injuries in the crash, with EMS attending to the ejected passengers while fire crews worked to free the two trapped patients.

All four were transported to hospital shortly afterwards.

Traffic was closed in the area for several hours afterwards, but it has since been reopened.

Police are investigating the cause of the crash.

Initial reports indicate that speed and alcohol were both factors in the crash.

Anyone who witnessed the crash is asked to contact the CPS Collision Reconstruction Unit at 403-567-4000 or Crime Stoppers.