Investigators are trying to learn more about the motivation behind the actions of two teenage girls who caused the shut down of a major Calgary highway on Thursday evening.

Police were called to Memorial Drive at about 5:00 p.m. for reports that two girls were sitting on the railing of the overpass, dangling their feet over the bridge that spans six lanes of traffic.

As a result, authorities closed down both directions of Deerfoot Trail to protect public safety.

After a short period of time, the girls were negotiated back off the bridge and taken into custody.

Deerfoot Trail reopened to  traffic shortly after 5:30 p.m. The closure lasted less than 10 minutes.

CPS officials are warning motorists of major delays in the area.

No one was injured in the incident.