The second accident involving a car and a motorcycle occurred around 7:15 p.m. near the intersection of Howe Avenue and Grove Street, police said.
The motorcyclist, Robert Freiler, 53, was transported to Bridgeport Hospital.
Shelton police, fire and EMS responded to the scene.
The earlier accident happened about a half-mile away on River Road.
Anyone who witnessed either accident is asked to contact the Shelton Police Department Traffic Division at 203-924-1544.
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