More than 7,000 Orem homes were without electricity for about an hour Wednesday evening when one of Utah Power & Light's main power lines went out.

According to a UP&L official, an unknown problem with an underground cable near Orem Boulevard and Center Street shortly after 5 p.m. caused a power outage in north and central Orem. UP&L officials were able to switch to a backup power source, and some power was restored within an hour. It took about 1 1/2 hours to restore all power.Gerald Nielsen, public information officer for Orem police, said a section of road near the intersection of Orem Boulevard and Center Street was raised about 6 inches by an underground explosion. Several people within a four-block radius reported feeling the ground shake and seeing smoke coming from manholes.

The outage also caused severe traffic congestion at the city's major intersections. Several off-duty police officers were called in to direct traffic. Nielsen said the congestion resulted in one serious accident at the intersection of 400 East and Center Street.

UP&L officials said they will not know the exact cause of the outage until the cable is dug up. It will take officials about two days to dig the cable up and repair the problem.