Caltrain is running behind schedule this morning after a northbound train broke down between Burlingame and Millbrae, a spokeswoman said.
Train No. 313 experienced mechanical difficulties on its way to San Francisco at about 7:40 a.m., according to Caltrain spokeswoman Christine Dunn.
There were approximately 720 passengers on board, according to Dunn.
The train was repaired by about 7:45 a.m., and northbound trains were running about 20 minutes late as a result of the delay.