MRT spokesman Mariano Gui, said the small blast occurred before the cable power snapped, causing fear and panic among the commuters.
The cause was the short-circuiting of catenary cable supplying power to a southbound train as it approached the GMA-Kamuning station at around 12:30 p.m.
Southbound trains of the MRT became fully operational in the afternoon after being limited to operate from Shaw Boulevard to Taft Avenue stations.
There was no interruption for northbound trains.
The affected train had to be towed to the Shaw Boulevard station where it received the needed repairs. After about an hour of troubleshooting, MRT technical men were able to resume partial operations of the entire system with passengers having to disembark at the Shaw Boulevard station.
A similar incident occurred last June 28, when the catenary cable likewise snapped and exploded causing alarm to the passengers to a northbound train in the middle of the Guadalupe and Buendia stations.
MRT officials quickly attributed the incident to the maintenance problems of the MRT due to its daily wear and tear.
Thousands of passengers of the MRT were also inconvenienced by a system failure during the Monday morning rush-hour.
MRT general manager Roberto Lastimoso said the malfunction of the train was caused by an "under voltage" in turn caused by a fluctuation in the power current supply.
As in last Monday’s MRT breakdown, countless inconvenienced passengers bewailed yesterday’s system failure.
Others said MRT personnel may need to undergo emergency response seminars after the way they handled yesterday’s incident.
Matthew de Guzman, 23, a call center agent in Makati City, said he was in a coach where the trouble originated. Passengers saw a spark at left side of the first coach of the train.
"As we reached the next station, there was smoke in the coach. Although it was not crowded, people panicked," he said,
When the passengers alighted from the train, an operator at the station asked passengers to wait inside the station as mechanics tried to fix the train.
Ten minutes later, De Guzman said, passengers ran and screamed when wires that supply power for the system exploded.
It was only then that the stranded passengers were ordered to leave the station.
"They should not experiment with passengers around because it could be very dangerous," he said.
De Guzman said the MRT staff should never allow passengers near the train when being repaired. — With Edu Punay