SAN DIEGO (CNS) - A construction crew accidentally ruptured a water main under a downtown street alongside Horton Plaza today, sending a muddy wash spewing over the roadway and into some nearby storefronts.

The mishap at First Avenue and West F Streetoccurred shortly after 10 a.m., as private-sector personnel hired by the city worked to replace a section of 16-inch-diameter concrete pipeline, according to the San Diego Public Utilities Department.

The resulting surge of water "looked like a huge fountain," PUC spokesman Arian Collins said.

It took city crews about 45 minutes to halt the overflow.

The accident cut off water service to about five commercial properties along First Avenue between F and G street. The block also was closed to through traffic pending repairs and cleanup.

The water main was expected to be back on line and the roadway open again by early evening, Collins said.