WWII munitions lurk near Tacony-Palmyra Bridge

Families flocked to the drive-in near the Tacony-Palmyra Bridge for four decades. In its heyday, cars packed with children lined up on Route 73 to get in.

The marquee trumpeted a smattering of hits: Mel Brooks' comic masterpiece

Blazing Saddles

was screened there in 1974.

More often it was home to cinematic bombs. The big-bug epic

Empire of the Ants

, starring Joan Collins, had a brief run in 1977.

No one suspected bombs of a different sort lay underneath the parked station wagons.

During World War II, the site served as a top-secret U.S. Army proving ground.

Last year, Palmyra began a cleanup of the 60-acre drive-in with an eye toward redevelopment. The site - nearly a third of Palmyra, according to the borough mayor - is owned by National Amusements. National Amusements, which runs 1,800 movie theaters, is owned by the media giant Viacom Inc.

"We knew there could be leftover shells," Palmyra Mayor John Gural said yesterday. "But what we found was a minefield. It really is mind-blowing."

Workers have unearthed 180 shells, Gural said.

"We expected to find one or two," he said.

All of the shells have live detonators, he said, though not all contain high explosives. Many are filled with wax to simulate the weight of a real shell.

"Because it was a hush-hush operation, the Army said they wouldn't have left anything behind for 'the enemy to find,' " Gural said. "I guess that didn't include the residents of Palmyra."

Gural said it was difficult to find a specialist to remove the munitions.

"Most companies that do this work are in the Middle East right now, in Iraq or Afghanistan," he said.

Each Thursday workers from MMG, a Tennessee firm, carefully explode the shells at the drive-in site.

During the 1940s, a 25-acre plot in the shadow of the bridge served as a target for antitank weapons developed at Philadelphia's Frankford Arsenal.

The Army also lobbed howitzer shells at the site from across the river, according to published reports.

After the war, the Army abandoned the site. The grounds were paved over and opened as the Tacony Palmyra Bridge Drive-In in 1957.

The drive-in closed in 1986. National Amusements leased the lot for a flea market. In March, the flea market was suddenly shuttered on Palm Sunday, when the state declared the site unsafe for the public. The closing stranded dozens of market vendors.

Since then explosives experts have combed only 65 percent of the site. Gural expects it will take two more months to complete the job and an additional nine months to remove other environmental hazards.

The state has paid $4.6 million so far to clean it up, Gural said. Uncovering the munitions has cost nearly $2 million and the tab keeps growing.

"We have to reclaim this land," Gural said. "It's the last piece of undeveloped property within the town limits."

Palmyra officials hope to lure the former Expo Center, formerly based in Fort Washington, to build on the property.

"We don't want to put residential housing on top of a minefield," Gural said.

The town is also wooing NASA in hopes the space agency will build a Challenger space education center there.

"There could even be a display about bombs in the parking lot," Gural said and laughed.

But Gural isn't joking about National Amusements and Viacom.

"Their only contribution has been to agree to shut down their flea market operation," he said.

National Amusements and Viacom did not return calls or e-mails requesting comment.

The state is shouldering the entire cost of the cleanup, Gural said, and the residents of Palmyra are suffering all the headaches.

When the project is finished, Palmyra wants to buy the land.

"We're increasing the value of the property," Gural said. "Of course, it's a public-safety issue, but Viacom gets a free ride."