Portland is hosting a major training exercise this weekend that will involve the simulated crash of a jet at the Portland International Jetport.

The drill will be held Saturday from 9 a.m. to 3 p.m., during which time the northbound lanes of the Veterans Memorial Bridge from South Portland to the Fore River Parkway will be closed.

Motorists should expect delays and many emergency vehicles on the Fore River Parkway and on Commercial Street, according to a city release.

The drill scenario envisions the crash of an inbound plane into the Fore River south of the Veterans Memorial Bridge.

The drill is required by the Federal Aviation Administration every three years to test the jetport’s emergency plans.