At least two seemingly credible witnesses reported seeing a man Tuesday afternoon walking on the pedestrian bridge over Interstate 80 at University Avenue in Berkeley carrying a long gun, prompting a massive, hours-long manhunt that turned up nothing. As KRON 4 reported, the search started after reports of the man — described as a white or Hispanic man in his 40s wearing a yellow shirt — first came in at 12:19 p.m.

CHP officers, Berkeley police, a SWAT team, a chopper, and East Bay Regional Parks District Police all were on the scene, searching the area of Frontage Road and McLaughlin Eastshore State Park, where the man was last seen heading. Frontage Road was shut down most of Tuesday afternoon between Gilman and University, and part of University Avenue was shut down much of the day as well, leading to heavy congestion. At one point, a drone was employed to fly over areas of the park.

As Berkeleyside reported, the sighting of the man prompted the evacuation of 140 children from a day camp at the Nature Center in the Berkeley Marina.

After six hours of searching, there was no further sighting or evidence of the man, and the EBRPD police called off the search just after 6 p.m.

Speaking to NBC Bay Area, Berkeley Police Sgt. Andrew Frankel said, "We had two very legitimate witnesses who gave good descriptions. That led me to believe they saw something."

He added to KRON 4 that it was a better-safe-than-sorry situation, and "Nowadays you can't be too careful."