Stuck on I-5 southbound near Mount Vernon? Here’s why.

Crews detoured traffic on Interstate 5 for several hours Saturday for a man who was “ranting and raving” on the overpass above the freeway at East Blackburn Road, according to the state Department of Transportation.

The incident led to the closure of all southbound lanes at around 5:30 a.m., the department said in a report. A detour was taking traffic off the interstate nearly a mile north of Blackburn at Kincaid Street, said Ally Barrera, a Department of Transportation spokeswoman.

The road was cleared at around 9:30 a.m., she said. By that point, Barrera added, traffic was backed up by about 5 miles, to the intersection with Highway 20.

The man on the overpass appeared to be under the influence of something, Barrera said, and was carrying a 2-by-4. At one point, she added, he sat down on the edge of the overpass.

For the safety of police, drivers, and the man himself, the road was closed and police waited until they could safely approach the man, Barrera said. He was later arrested.

Further information on the incident was not immediately available.

Kyle Mittan: 360-756-2803, @KyleMittan