WASHINGTON COUNTY, Pa. -- All lanes of Interstate 70 are open again, following a partial overpass collapse that sent tons of concrete crashing onto the highway in South Strabane Township, Washington County.

A witness told WTAE Channel 4 Action News no one was on the Lakeview Drive Bridge when a 20- to 30-foot section of the guiderail and cement on both sides of the bridge -- which spans I-70 -- fell to the ground on Tuesday evening.

A handful of people suffered minor injuries, and some cars were damaged.

PennDOT Deputy Secretary Gary Hoffman held a news conference early Wednesday afternoon in which he said that the bridge was last inspected as part of national inspection requirements in March 2004 and found to be structurally deficient at that time.

Other information released by Hoffman regarding the bridge included:

• About 6 p.m. Tuesday night, the downstream fascia beam collapsed.
• The beam was 88 feet long and weighed about 60 tons.
• The beam broke over a traffic lane where the bridge had been hit over time with over-height vehicles.
• The legal limit for bridges in Pennsylvania is 13.5 feet. Occasionally PennDOT permits higher clearance. The bridge's clearance was 14 feet 5 inches.
• The bridge is about 45 years old, built in 1960.
• Deterioration of the bridge has been noted over time.
• The emergency contractor will remove the beam from the road around 3 p.m. Wednesday afternoon. They'll then open the westbound lanes.
• Michael Baker Consulting Firm engineers are involved in investigation.
• There are other bridges in the area designed in the same way.

Hoffman said, "I have confidence in our engineers and in our bridge inspection program."

Hoffman also said that PennDOT has exhaustive data on all 25,000 bridges that the department is responsible for maintaining.

Depending on the results of the Lakeview Drive Bridge investigation, PennDOT may also decide to look at other similar bridges in the state, Hoffman said.

The bridge was next due for a biennial inspection in March 2006. An interim inspection was done in August 2005, and noted the following:

• The bridge was able to support itself and carry over 50 tons.
• The bridge was labeled as a "structurally deficient bridge."
• The bridge was not load posted.

Hoffman also said the bridge will need to be demolished.