This ambulance chaser must have been brain-dead.

A city marshal slapped a tire boot on an ambulance in Brooklyn last week, preventing it from responding to emergencies for hours, stunned corps members like Kelly Gums told The Post.

“Hopefully no one lost their life,” said James “Rocky” Robinson, commander of the Bedford-Stuyvesant Volunteer Ambulance Corps. “I don’t understand how they have the audacity to do this!”

The ambulance was parked in front of the Corps base along Greene Avenue on Tuesday morning when city marshal Robert Solimine slapped it with an immobilizing steel boot — placed on vehicles whose owners rack up $350 or more of unpaid tickets.

“How on earth can an emergency vehicle get a boot and still save lives?” fumed corps member Lem Peterkin. “I thought someone was playing a joke — but then reality set in.”

Robinson, 73, immediately sounded the alarm, reaching out to activist and Corps volunteer Kirsten John Foy, who alerted Chief Gerald Nelson of Brooklyn North precinct, who got the word out to the Department of Finance, on whose behalf city marshals collect unpaid debts.

“Emergency vehicles should never be booted for outstanding parking tickets,” said Department of Finance spokesman Owen Stone.

“When we learned of the issue, we ordered an immediate release of the boot.”

Solimine had no comment, but

Michael Woloz, a spokesman for the NYC Marshals Association, called the boot blunder a “unique instance.”

“The vehicle’s markings as a volunteer ambulance raised a question as to whether it was in fact defined as an emergency vehicle. Regrettably, the booting of the vehicle, turned out to be inappropriate,” he said.

But while the ambulance boot was a goof up — the city said that four non-emergency vehicles associated with the Bed Stuy corps owe $747 in unpaid tickets.

Robinson, a retired FDNY captain, said his drivers may have been unfairly targeted.

“I’m sure they wouldn’t have the nerve to do this to Hatzolah,” he said, referring to the volunteer corps that serves Orthodox Jewish neighborhoods.

“We are training kids to get off the street to be life savers instead of life takers — and someone doesn’t like that,” he added.