Given a reference text about Teodoro "Teddy" de Villa Diaz, tell me how he died and how old he was when he died.

Teodoro "Teddy" de Villa Diaz (1 April 1963 – 21 August 1988) was a Filipino musician and composer, best known as the founder and original guitarist of The Dawn.

As a composer, he co-wrote the band's first single "Enveloped Ideas" and their well-known hit "Salamat", which was released posthumously in 1989.[2] He played guitar on the albums The Dawn (1986) and I Stand With You (1988). Aside from being a guitarist, he played keyboards as credited on The Dawn's 1986 debut album.[citation needed]

At the height of his career and at the peak of The Dawn's popularity in the late 1980s, he was stabbed to death in front of his girlfriend's house by two bystanders who were allegedly under the influence of drugs and alcohol.

Teodoro "Teddy" de Villa Diaz was stabbed to death by two bystanders when he was 25 years old.