Big Bridge Goes Boom: Parkway East Demolition Explained Simply

What Happened?

Imagine a giant Lego bridge that got too old to use safely. On Thursday morning, workers used explosives to knock down the Parkway East bridge (also called the Commercial Street Bridge) on Interstate 376.

This happened one day later than planned. Why? Because on Wednesday evening, PennDOT (the Pennsylvania Department of Transportation — the people in charge of roads) decided to wait. The contractor (the building company) needed more time to make sure everything was super safe before the big boom.

Important Point: You can watch the live video of the blast in the video player above, and a replay in the video below!

What Comes Next?

After the dust and broken pieces are cleaned up, construction crews will do something cool: they will slide a brand-new bridge into the same spot where the old one was.

PennDOT says this slide will be one of the largest sideways bridge slides in the whole state of Pennsylvania!

Road Closed! (For a While)

Interstate 376 is shut down between two places:

• The Squirrel Hill Tunnel
• The Edgewood/Swissvale interchange (an exit where roads meet)

The road is planned to stay closed until August 3.

Important Point: If you drive here, you must use a detour (a different route). We list those below!

A Little History of the Old Bridge

According to Historic Pittsburgh (a website by the University of Pittsburgh’s library), the old bridge was built a long time ago:

• Started: April 1948
• Finished: April 1951

Here are its simple stats:

• 3 big arches, each 170 feet long (like 17 school buses!)
• 12 smaller side pieces (called approach spans), each 28 feet long
• Total length (with the longest ramp): 846 feet
• The road part sat 85 feet above the arch and was 68 feet wide

Detours: How to Drive Around the Closure

If you need to drive this area, here are the easy step-by-step turns.

Interstate Detour Westbound (going toward downtown)

1. From westbound I-376, take Exit 78B (Wilkinsburg) toward PA 8 north
2. Merge onto Route 8 (Ardmore Boulevard)
3. Continue straight onto Route 8 (Penn Avenue)
4. Turn left onto Fifth Avenue
5. After going through Oakland, take the ramp to the left for westbound I-376 (watch out for cars coming the other way!)
6. Merge onto the Boulevard of the Allies and stay right to get on westbound I-376 toward downtown/Fort Pitt Bridge
7. Continue straight to merge onto westbound I-376

Interstate Detour Eastbound (going away from downtown)

1. From eastbound I-376, take Exit 72A (Forbes Avenue/Oakland)
2. Merge onto Forbes Avenue
3. Turn left onto South Bellefield Avenue
4. Turn right onto Fifth Avenue
5. Turn right onto Route 8 (Penn Avenue)
6. Bear right to continue on Route 8 (Ardmore Boulevard)
7. Take the ramp to 376/22/30 toward Pittsburgh/Monroeville
8. At the split, bear left to eastbound 376/22 toward Monroeville
9. Merge onto eastbound I-376

Local Detour Westbound (local roads toward downtown)

• From westbound I-376, take Exit 77 (Edgewood/Swissvale)
• At the end of the ramp, turn left onto South Braddock Avenue
• Continue onto the Rankin Bridge
• Turn right onto Route 837 (River Road)
• Continue onto Route 837 (Eighth Avenue)
• Turn right onto the Homestead Grays Bridge
• Continue onto Browns Hill Road
• Continue straight onto Beechwood Boulevard
• Follow signs for westbound I-376 toward Pittsburgh
• Take the ramp to westbound I-376 toward Pittsburgh

Local Detour Eastbound (local roads away from downtown)

• From eastbound I-376, take Exit 74A (Squirrel Hill/Homestead), continuing straight onto Beechwood Boulevard toward Homestead
• Continue straight onto Browns Hill Road
• Continue onto the Homestead Grays Bridge
• Turn left onto Route 837 (Eighth Avenue)
• Continue straight on Route 837 (River Road)
• Turn left onto the Rankin Bridge
• Continue onto South Braddock Avenue
• Bear right to merge onto eastbound I-376 toward Monroeville

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Summary

The old Parkway East (Commercial Street) bridge was blown up Thursday morning after a one-day safety delay. A new bridge will be slid in later — one of the biggest such projects in PA. I-376 is closed between Squirrel Hill Tunnel and Edgewood/Swissvale until Aug. 3. The old bridge dated from 1948–1951. Use the detour lists above if driving, and grab the WTAE app or newsletters for updates.

FAQ

Q: Why was the bridge explosion delayed?
A: PennDOT postponed it from Wednesday evening to Thursday morning so the contractor could finish safety preparations.

Q: How long is the road closed?
A: I-376 is closed between the Squirrel Hill Tunnel and Edgewood/Swissvale interchange, currently planned through August 3.

Q: What will happen to the bridge spot?
A: Crews will slide a new bridge onto the same I-376 alignment after debris is cleared; it’ll be among the state’s largest lateral slides.

Q: Can I still drive through there?
A: Not on I-376 directly — use the interstate or local detour routes listed in this article.

Q: How old was the demolished bridge?
A: Construction began April 1948 and finished April 1951, making it about 73 years old at demolition.