A sinkhole opened beneath a road in central Florida (search) on Saturday, swallowing four lanes of pavement and forcing the evacuation of 20 homes.

Volusia County officials had been watching the hole since Monday, when collapsed asphalt was noticed on Howland Boulevard near Deltona High School. Workers were pumping a cement mixture under the damaged road when the hole formed.

"All of the sudden, they started feeling rumblings in the ground," said Robert Rogers, deputy chief of the fire department in Deltona, about 25 miles southwest of Daytona Beach (search).

The ground opened up, destroying all four lanes. The hole grew to 50 feet deep and at least 150 feet wide.

"It has not stabilized yet, so I'm sure its going to get a lot bigger," Rogers said.

The sinkhole also threatened to take down a major power line and forced authorities to evacuate 20 homes near the electrical wires. Residents in all but three houses were expected to return Saturday night.

One house was in imminent danger of falling into the hole, Rogers said.